8-Self2

Self-Check 1-1Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 3/9/2012 5:21:18 PM

Points Awarded 16

Points Missed 1

Percentage 94%

1. An object which has its acceleration and velocity directions opposite is:

A. speeding up B. slowing down C. moving left D. moving right E. none of them

Points Earned: 1/1

Your Response: B

2. Can an object's velocity change direction when its acceleration is constant?

A. No, this is not possible because it is always speeding up. B. No, this is not possible because it is always speeding up or always slowing down, but it

can never turn around. C. Yes, this is possible, and a rock thrown straight up is an example. D. Yes, this is possible, and a car that starts from rest, speeds up, slows to a stop, and then

backs up is an example.

Points Earned: 1/1

Your Response: C

3. An object accelerates if it

A. changes the direction of its velocity but not the magnitude B. changes the magnitude of the velocity but not the direction C. changes its speed D. all of the above E. none of the above

Points Earned: 1/1

Your Response: D

4. A car starts for rest and in ten seconds is moving at 40 m/s. What is the car's acceleration?

A. 0.25 m/s2 B. 2.5 m/s2

C. 4.0 m/s2 D. 10 m/s2 E. 40 m/s2 F. none of the above

Points Earned: 1/1

Your Response: C

5. An object, accelerating from rest at a constant rate, travels over 28 m in 11 s. What is its final velocity?

A. 1.8 m/s B. 3.2 m/s C. 5.1 m/s D. zero E. none of the above

Points Earned: 1/1

Your Response: C

6. A car comes to a stop over a distance of 30.0 m after the driver applies the breaks. If the car decelerates at a constant rate of 3.50 m/s2, what was the car's original speed?

A. 10.2 m/s B. 14.5 m/s C. 105 m/s D. 210 m/s E. none of the above

Points Earned: 1/1

Your Response: B

7. A stone is thrown straight up. What is its acceleration at the top of its trajectory?

A. 0 m/s2 B. about 5 m/s2 C. about 10 m/s2 D. about 20 m/s2 E. about 50 m/s2 F. Cannot be determined

Points Earned: 1/1

Your Response: C

8. While the stone in the question above is rising:

A. its acceleration is upward and decreasing B. its acceleration is upward and constant C. its acceleration is upward and increasing

D. its acceleration is zero E. None of the above

Points Earned: 1/1

Your Response: E

9. An object is thrown upward with an initial velocity of 32.1 m/s. What is its velocity in 4.0 s?

A. -7.2 B. 11.0 C. 7.1 D. -4.6

Points Earned: 1/1

Your Response: A

10. When the object in the question above reaches its maximum height, it is true of the acceleration, a, and the velocity, v, that

A. both its acceleration and velocity are zero B. both its acceleration and velocity change sign C. velocity is equal to zero, but acceleration is not D. acceleration is equal to zero, but velocity is not E. none of the above

Points Earned: 1/1

Your Response: C

11. While accelerating at a constant rate from 12.0 m/s to 18.0 m/s, a car moves over a distance of 60.0 m. How much time does it take?

A. 1.00 B. 2.50 C. 4.00 D. 4.50 E. none of the above

Points Earned: 1/1

Your Response: C

12. A sports car accelerates at a constant rate from rest to a speed of 90 km/hr in 8 s. What is its acceleration?

A. 3.1 m/s2 B. 4.2 m/s2 C. 5.3 m/s2 D. 6.7 m/s2 E. none of the above

Points Earned: 1/1

Your Response: A

13. What distance does a train travel while slowing from 28 m/s to zero in 12 s?

A. 168 m B. 178 m C. 236 m D. 291 m E. none of the above

Points Earned: 1/1

Your Response: A

14. What upward velocity must a basketball player have to jump 1.6 m off the floor?

A. 2.3 m/s B. 3.8 m/s C. 4.9 m/s D. 5.6 m/s E. none of the above

Points Earned: 1/1

Your Response: D

15. A cart is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 2.0 m/s2. What is the final velocity after 6.0 s?

A. 10 m/s B. 12 m/s C. 16 m/s D. 17 m/s

Points Earned: 0/1

Your Response: C

16. A train moves along a straight track and its position vs. time looks like:

Which graph best depicts the train's velocity vs. time?

A. A B. B C. C D. D

Points Earned: 1/1

Your Response: D

17. The graph show positions as a function of time for two trains running on parallel tracks.

Which statement is true:

A. At time tC, both trains have the same velocity. B. Both trains speed up all the time. C. Both trains have the same velocity at some time before tc.

D. At some time, both trains have the same acceleration. E. None of the above statements is true.

Points Earned: 1/1

Your Response: C

Quiz 1-1Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 6/25/2012 1:13:31 PM

Points Awarded 17

Points Missed 1

Percentage 94%

1. A car decelerates at 3m/s2 for 4s. How far does it its initial velocity is 15 m/s?

A. 18 m B. 20 m C. 28 m D. 36 m E. 84 m

Points Earned: 1/1

Correct Answer: D

Your Response: D

2. Motion is called uniform if the object

A. moves in a circle B. moves equal distances in equal times C. does not change direction

D. moves in a straight line

Points Earned: 0/1

Correct Answer: B

Your Response: D

3. Kathleen walks 27.5 m to the left, then 11.2 m to the right and finally 17.6 m to the left in a time of 200 s. Her displacement is _____ m.

A. 0.281 B. -33.9 C. 33.9 D. 56.3

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. If you drive west at 20 km/h for one hour, then drive east at 15 km/h for one hour, your net displacement will be

A. 5 km east B. 35 km west C. 35 km east D. 5 km west

Points Earned: 1/1

Correct Answer: D

Your Response: D

5. It takes about 11 minutes to get to the observatory, which is 11 miles away. What is the average speed for the trip in this case?

A. 100 mph B. 1 mph C. 10 mph D. 60 mph E. 55 mph

Points Earned: 1/1

Correct Answer: D

Your Response: D

6. Consider the following five graphs (note the axes carefully). Which of these represent(s) motion at constant speed?

A. IV only B. IV and V only C. I, II, and III only D. I and II only E. I and IV only

Points Earned: 1/1

Correct Answer: E

Your Response: E

7. If the velocity versus time graph of an object is a horizontal line parallel to x-axis, the object is

A. moving with constant non-zero speed. B. moving with constant non-zero acceleration. C. at rest. D. moving with infinite speed.

Points Earned: 1/1

Correct Answer: A

Your Response: A

8. An object moves with velocity in +x-direction with constant acceleration a. After 3 seconds, its acceleration changes to a constant value -a. Which of the following statements is true regarding the motion of the object upon this sudden change in acceleration?

A. Its velocity and displacement become negative. B. Its velocity is positive but its displacement is negative. C. Its position and velocity decrease. D. Its position increases, but its velocity decreases. E. Its position and velocity increase

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. A car moving in a straight line with an initial velocity of 12.0 m/s accelerates at a uniform rate until it reaches a velocity of 18.0 m/s. If it covers a distance of 60.0 m while doing this then the time interval was ______ s.

A. 2.00 B. 3.00 C. 4.00 D. 4.50

Points Earned: 1/1

Correct Answer: C

Your Response: C

10. A locomotive slows from 28 m/s to zero in 12 s. What distance does it travel?

A. 168 m B. 196 m C. 336 m D. 392 m

Points Earned: 1/1

Correct Answer: A

Your Response: A

11. A car with good tires on a dry road can decelerate at about 5.0 m/s2 when braking. If the car is traveling at 55 mi/h, what is the stopping distance?

A. 60 m B. 120 m C. 300 m D. 5.5 m

Points Earned: 1/1

Correct Answer: A

Your Response: A

12. A car goes from zero to 50 m/s in 10 s. What is its average acceleration?

A. 9.8 m/s2

B. 32 ft/s2 C. 50 m/s D. 5 m/s2

Points Earned: 1/1

Correct Answer: D

Your Response: D

13. A ball is pushed with an initial velocity of 4.0 m/s. The ball rolls down a hill with

a constant acceleration of 1.6 m/s2. The ball reaches the bottom of the hill in 8.0 s. What is the ball’s velocity at the bottom of the hill?

A. 10 m/s B. 12 m/s C. 16 m/s D. 17 m/s

Points Earned: 1/1

Correct Answer: D

Your Response: D

14. Two objects of different mass are released simultaneously from the top of a 20 m tower and fall to the ground. If air resistance is negligible, then which of the following statements best applies?

A. The greater mass hits the ground first. B. Both objects hit the ground together. C. The smaller mass hits the ground first. D. No conclusion can be made with the information given

Points Earned: 1/1

Correct Answer: B

Your Response: B

15. John throws a rock down with speed 14 m/s from the top of a 30-m tower. If g = 9.8 m/s2 and air resistance is negligible, what is the rock’s speed just as it hits the ground?

A. 12 m/s B. 28 m/s C. 350 m/s D. 784 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B

16. A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.00 s?

A. 9.8 m/s upward. B. 9.8 m/s downward. C. zero D. 19.6 downward.

Points Earned: 1/1

Correct Answer: B

Your Response: B

17. An object in free fall from rest will fall m in the first 2 seconds?

A. 9.8 B. 19.6 C. 4.9 D. 29.4 E. 14.7

Points Earned: 1/1

Correct Answer: B

Your Response: B

18. An object is thrown straight upward from the edge of a cliff which is 20 m high. The object rises 15 m and then falls to the base of the cliff. Choosing the positive x to be up, the rock's displacement is:

A. 20 m B. -15 m C. -20 m D. 55 m

Points Earned: 1/1

Correct Answer: C

Your Response: C


Points Awarded 13

Points Missed 5

Percentage 72%

1. A rock is thrown upward from the edge of a cliff which is 20 m high. The object rises 15 m and then falls to the ground. If the positive direction of the x is up, what is the rock's displacement?

A. 20 m B. -15 m C. -20 m

D. 55 m

Points Earned: 1/1

Correct Answer: C

Your Response: C

2. If an object moves at constant speed, which of the following increases with time?

A. average velocity B. instantaneous velocity C. distance traveled D. direction E. acceleration

Points Earned: 1/1

Correct Answer: C

Your Response: C

3. If the average speed of a plane is 500 km per hour, how long will it take to fly 125 km?

A. 4.00 h B. 2.00 h C. 0.50 h D. 0.25 h

Points Earned: 1/1

Correct Answer: D

Your Response: D

4. If you drive west at 20 km/h for one hour, then drive east at 15 km/h for one hour, your net displacement will be

A. 5 km east B. 35 km west C. 35 km east D. 5 km west

Points Earned: 0/1

Correct Answer: D

Your Response: A

5. Which of the following is not possible? An object

A. has zero velocity and non-zero acceleration B. travels with a northward velocity and a southward acceleration C. travels with a constant velocity and time-varying acceleration D. travels with a time-varying velocity and constant acceleration

Points Earned: 0/1

Correct Answer: C

Your Response: A

6. A train moves along a straight track and its position vs. time looks like:

Which graph best depicts the train's velocity vs. time?

A. A B. B C. C D. D

Points Earned: 1/1

Correct Answer: D

Your Response: D

7. A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the acceleration of the ball is zero. We know that at t = 5 s,

A. the slope of the curve is non-zero. B. the velocity of the ball is not changing. C. the curve is not crossing the time axis. D. the curve is at v = 0, t = 0.

Points Earned: 1/1

Correct Answer: B

Your Response: B

8. An object which has its acceleration and velocity directions opposite is:

A. speeding up B. slowing down C. moving left D. moving right E. none of them

Points Earned: 1/1

Correct Answer: B

Your Response: B

9. A car rolls down a 2.40 m long ramp in a time of 1.68 s. The magnitude of the average acceleration of the car is ________ m/s‚.

A. 1.70 B. 3.40 C. 0.850 D. 2.09

Points Earned: 0/1

Correct Answer: A

Your Response: B

10. A cart, accelerating from rest at a constant rate, experiences a displacement of 44 m in 20 s. What is the final velocity after 20 s?

A. 1.1 m/s B. 2.2 m/s C. 4.4 m/s D. zero

Points Earned: 1/1

Correct Answer: C

Your Response: C

11. An object slides on a level surface in the +x direction at a speed of 1.7 m/s. It slows and comes to a stop with a constant acceleration of -2.45 m/s2. What distance did the object travel?

A. 0.25 B. 0.59 C. 0.43 D. Impossible to determine without knowing the mass of the object.

Points Earned: 1/1

Correct Answer: B

Your Response: B

12. A car starting from rest moves with constant acceleration of 2 m/s2 for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of -2 m/s2. How far does it travel?

A. 200 m B. 300 m C. 400 m D. 500 m

Points Earned: 1/1

Correct Answer: C

Your Response: C

13. An object initially at rest moves horizontally at a constant acceleration so that its speed after 10 seconds is 40 m/s. How far has it traveled after those 10 seconds?

A. 200 meters B. 100 meters C. 400 meters D. 300 meters

Points Earned: 1/1

Correct Answer: A

Your Response: A

14. A ball that is thrown straight up into the air reaches a maximum height and begins to fall down. At the top of the ball's path the acceleration of gravity changes in ________ when the velocity of the ball changes direction. Assume that the direction of the positive axis does not change.

A. neither magnitude nor direction B. magnitude, but not direction C. direction, but not magnitude D. both magnitude and direction

Points Earned: 0/1

Correct Answer: A

Your Response: D

15. If vertical distance can be found from the equation: y = ½ g t2 , how far can an object drop in two seconds?

A. 4.9 meters. B. 9.8 meters. C. 4.7 meters. D. 19.6 meters.

Points Earned: 1/1

Correct Answer: D

Your Response: D

16. A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.00 s?

A. 9.8 m/s upward. B. 9.8 m/s downward. C. zero D. 19.6 downward.

Points Earned: 1/1

Correct Answer: B

Your Response: B

17. Water drips from rest from a leaf that is 20 meters above the ground. If air resistance is neglected, the approximate speed of each water drop when it hits the ground is

A. 10 m/s B. 15 m/s C. 20 m/s D. 30 m/s

Points Earned: 1/1

Correct Answer: C

Your Response: C

18. An object is thrown straight upward from the edge of a cliff which is 20 m high. The object rises 15 m and then falls to the base of the cliff. Choosing the positive x to be up, the rock's displacement is:

A. 20 m B. -15 m C. -20 m D. 55 m

Points Earned: 0/1

Correct Answer: C

Your Response: B

Self Check 1-2Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 3/11/2012 1:19:23 PM

Points Awarded 20

Points Missed 0

Percentage 100%

1. A helicopter is flying at 40 m/s at an altitude of 100 m. If a ball is released from the helicopter, with what velocity will it hit the ground?

A. 40 m/s B. 50 m/s C. 60 m/s D. 70 m/s

Points Earned: 1/1

Your Response: C

2. Consider the following statements regarding idealized projectile motion: (ignore air resistance).

-1. The horizontal component of acceleration is always zero-2. The vertical component of acceleration is always downward-3. The vertical component of acceleration is always the acceleration due to gravity (g)-4. The horizontal component of the velocity is constant-5. The vertical component of the velocity is never equal to zero. Which of these statements is ALWAYS true (for idealized projectile motion)?

A. They are all true B. 1, 2, 3, and 4C. 1, 2, 4, and 5D. 1, 3, 4, and 5E. a, b, c and d above are all incorrect answers to this question

Points Earned: 1/1

Your Response: B

3. Which of the following statements is true for two balls thrown in the air at different angles with the horizontal?

A. the ball making the steeper angle spends more time in the air B. the ball making the shallower angle spends more time in the air C. the time of flight does not depend on the initial speed given each ball. D. the time of flight depends on the mass of each ball.

Points Earned: 1/1

Your Response: A

4. A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. It hits the ground in 4.3 s. What is the height of the cliff?

A. 22 m B. 43 m C. 77 m D. 91 m

Points Earned: 1/1

Your Response: D

5. A projectile is launched with an initial velocity of 60.0 m/s at an angle of 37.0o above the horizontal. What is the maximum height reached by the projectile?

A. 23 m B. 46 m C. 67 m D. 92 m

Points Earned: 1/1

Your Response: C

6. A soccer ball is kicked with a velocity of 25 m/s at an angle of 45ø above the horizontal. What is the vertical component of its acceleration as it travels along its path?

A. 9.80 m/s2 downward B. (9.80 m/s2)*sin (45ø) downward C. (9.80 m/s2)*sin (45ø) upward D. (9.80 m/s2) upward

Points Earned: 1/1

Your Response: A

7. A pilot drops an object from a plane flying horizontally. Where will the plane be located when the object hits the ground? Ignore air resistance.

A. behind and above the bomb. B. over the bomb. C. in front and above of the bomb. D. depend on the speed of the plane when the bomb was released.

Points Earned: 1/1

Your Response: B

8. A stone is thrown horizontally from the top of a tower at the same instant that another stone is dropped vertically. Which object is having a greater speed when it hits the ground?

A. It is impossible to tell from the information given. B. The first stone C. The second stone D. Neither, since both of them will hit the ground at the same time.

Points Earned: 1/1

Your Response: B

9. A basketball is shot towards the basket from the foul line. At the top of its trajectory

A. both the x and y components of velocity are zero B. neither the x nor the y components of velocity are zero C. only the x component of velocity is zero D. only the y component of velocity is zero

Points Earned: 1/1

Your Response: D

10. A ball thrown horizontally from the top of a building 24 m above the ground, strikes the ground at the distance of 18 m from the base of the building. What was its initial velocity? (Use g = 10 m/s2.)

A. 6.10 m/s B. 7.40 m/s C. 8.22 m/s D. 8.96 m/s

Points Earned: 1/1

Your Response: C

11. The horizontal and vertical components of the initial velocity of a projectile are 50 m/s and 120 m/s respectively. What is the magnitude of the initial velocity?

A. 110 m/s, B. 130 m/s, C. 150 m/s, D. 170 m/s

Points Earned: 1/1

Your Response: B

12. A projectile launched at an angle follows a _____ path.

A. parabolic B. straight C. hyperbolic D. changing

Points Earned: 1/1

Your Response: A

13. How far below an initial straight-line path will a projectile fall in 1 second in the absence of air resistance?

A. 4.9m B. 9.8m C. 19.6m

D. not enough information is given to answer this question

Points Earned: 1/1

Your Response: A

14. A bullet fired horizontally hits the ground in 1 second. Neglecting air resistance, if it had been fired with a higher speed in the same direction, it would have hit the ground

A. in more than 1 second B. in less than 1 second C. in 1 second D. not enough information given

Points Earned: 1/1

Your Response: C

15. For an object launched from a horizontal surface, the time it stays in the air depends upon

A. the initial y component of velocity B. the initial x component of velocity C. both the initial x and y components D. neither of the initial components

Points Earned: 1/1

Your Response: A

16. A flare is dropped from an airplane flying horizontally at a speed of 140 m/s at a height of 490 m. If there is no air resistance the flare will reach the ground in _______ s.

A. 10.0 B. 20. C. 50.0 D. 100

Points Earned: 1/1

Your Response: A

17. A rock is kicked horizontally at a speed of 10 m/s from the edge of a cliff. The cliff is 25 m high. The length of time that it takes the rock to reach the ground is

A. 0.4 B. 2.3 C. 2.5 D. none of these are correct

Points Earned: 1/1

Your Response: B

18. A baseball thrown from the outfield is released from shoulder height at an initial velocity of 29.4 m/s at an initial angle of 30 o with respect to the horizontal. What is the

maximum vertical displacement that the ball reaches during its trajectory?

A. 11.0 m B. 9.8 m C. 22.1 m D. 44.1 m

Points Earned: 1/1

Your Response: A

19. A ball is thrown into the air at some angle. At the very top of the ball's path, its velocity is

A. entirely vertical. B. entirely horizontal. C. both vertical and horizontal. D. There's not enough information given to determine.

Points Earned: 1/1

Your Response: B

20. A rock is thrown horizontally off the roof of a building at the same instant a second rock is dropped from the same height. Which one hits the ground first?

A. both hit same time, B. first, C. second, D. more info needed

Points Earned: 1/1

Your Response: A

Quiz 1-2Your response has been submitted successfully.

Points Awarded 8

Points Missed 4

Percentage 67%

1. A projectile launched at an angle follows a _____ path.

A. parabolic B. straight C. hyperbolic D. changing

Points Earned: 1/1

Correct Answer: A

Your Response: A

2. Which of the following statements is true for two balls thrown in the air at different angles with the horizontal?

A. the ball making the steeper angle spends more time in the air B. the ball making the shallower angle spends more time in the air C. the time of flight depends on the initial speed given each ball. D. the time of flight depends on the mass of each ball. E. a and c F. c and d

Points Earned: 0/1

Correct Answer: E

Your Response: A

3. A ball is thrown into the air at some angle. At the very top of the ball's path, its velocity is

A. entirely vertical. B. entirely horizontal. C. both vertical and horizontal. D. There's not enough information given to determine.

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. A baseball is thrown by the center fielder (from shoulder level) to home plate where it is caught (on the fly at shoulder level) by the catcher. At what point does the magnitude of the vertical component of velocity have its minimum value? (air resistance is negligible)

A. just after leaving center fielder’s hand B. just before arriving at catcher’s mitt C. at the top of the trajectory

D. magnitude of vertical component of velocity is constant

Points Earned: 1/1

Correct Answer: C

Your Response: C

5. Suppose you swim in a direction directly across a flowing river and end up at a distance downstream greater than the width of the river. How does your swimming speed compare to the flow rate of the river?

A. your swimming speed is faster than the river's speed B. the river's speed is greater than your swimming speed C. the river's speed and your swimming speed are the same D. this scenario is not possible

Points Earned: 0/1

Correct Answer: B

Your Response: A

6. A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stop watch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff?

A. 22 m B. 43 m C. 77 m D. 91 m

Points Earned: 1/1

Correct Answer: D

Your Response: D

7. A projectile is launched with an initial velocity of 60.0 m/s at an angle of 37.0o above the horizontal. What is the maximum height reached by the projectile?

A. 23 m B. 46 m C. 67 m D. 92 m

Points Earned: 1/1

Correct Answer: C

Your Response: C

8. A projectile is launched at an angle, such that the horizontal component of its initial velocity is 50 m/s and the vertical component is 120 m/s. What is the magnitude of the initial velocity?

A. 110 m/s, B. 130 m/s, C. 150 m/s, D. 170 m/s

Points Earned: 0/1

Correct Answer: B

Your Response: C

9. A rock is kicked horizontally at a speed of 10 m/s from the edge of a cliff. The cliff is 25 m high. The length of time that it takes the rock to reach the ground is

A. 0.4 s B. 2.3 s C. 2.5 s D. none of these are correct

Points Earned: 1/1

Correct Answer: B

Your Response: B

10. A baseball thrown from the outfield is released from shoulder height at an initial velocity of 29.4 m/s at an initial angle of 30 o with respect to the horizontal. What is the maximum vertical displacement that the ball reaches during its trajectory?

A. 11.0 m B. 9.8 m C. 22.1 m D. 44.1 m

Points Earned: 1/1

Correct Answer: A

Your Response: A

11. A stone is thrown at an angle of 30 o above the horizontal from the top edge of a cliff with an initial speed of 12 m/s. A stop watch measures the stone's trajectory time from top of cliff to bottom to be 5.6 s. How far out from the cliff's edge does the stone travel horizontally? (g = 9.8 m/s2 and air resistance is negligible.

A. 58 m B. 154 m C. 120 m D. 197 m

Points Earned: 1/1

Correct Answer: A

Your Response: A

12. A baseball is thrown from the outfield with an initial velocity of 29.4 m/s at an initial

angle of 30o. How far does it go?

A. 76.4 m B. 38.2 m C. 57.3 m D. 44.1 m

Points Earned: 0/1

Correct Answer: A

Your Response: C


Points Awarded 30

Points Missed 0

Percentage 100%

1. The mass of an object:

A. is slightly different at different locations on the Earth B. is a vector C. is independent of g D. is the same for all objects of the same size and shape E. can be measured directly and accurately on a spring scale

Points Earned: 1/1

Your Response: C

2. A 36-N net force acts on a 2.1-kg mass. What is the magnitude of the resulting acceleration?

A. 17 m/s2 B. 0.058 m/s2

C. 36 m/s D. 2.1 m/s2

Points Earned: 1/1

Your Response: A

3. Plato the Dog is attracted toward the center of the Earth by a 180 N gravitational force. The force of attraction of the Earth toward Plato is:

A. very very small. B. very very large. C. exactly 180 N.

Points Earned: 1/1

Your Response: C

4. Asteroids have been moving through space for billions of years. What is pushing them through the space?

A. Gravity. B. Rockets. C. Spinning motion. D. Nothing.

Points Earned: 1/1

Your Response: D

5. A ball is sitting at rest in the middle of a toy wagon. When the wagon is pulled forward, the ball rolls to the back of the wagon. What is the BEST reason why the ball rolls to the back of the wagon?

A. Newton’s Law of Inertia: The ball at rest tends to remain at rest unless there is an outside force.

B. Newton’s Law of Force and Acceleration: The ball’s acceleration is equal to the outside force divided by it’s mass.

C. Newton’s Law of Action - Reaction: When you pull the wagon forward, the wagon pulls back.

D. Conservation of Momentum: Which no outside force, momentum in the wagon-ball system is conserved.

Points Earned: 1/1

Your Response: A

6. In tearing a paper towel or a plastic bag, why is a sharp jerk more effective than a slow pull?

A. The inertia of a single sheet of paper is greater than the rest of the roll. B. The inertia of the whole roll resists the large acceleration of a sharp jerk. C. Paper towels and plastic bags are not designed to tear. D. It is actually more effective to pull slowly than to pull quickly.

Points Earned: 1/1

Your Response: B

7. Whirl a weight at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to …

A. continue to follow a circular path. B. follow a straight-line path. C. fall straight to the ground.

D. slap you in the face.

Points Earned: 1/1

Your Response: B

8. When we jump straight up, why do we land in our footsteps rather than at a location equal to the distance the Earth moves during our jump?

A. Actually, we do but the distance is too small to notice. B. By Newton's First Law, we are already moving with the Earth before the jump and

continue to move with the Earth during our jump. C. By Newton's Third Law, we are pushing on the Earth, so it has to come back to us with

the same amount of force. D. The conservation of momentum means there can be no motion because that would result

in a change in the motion after we jump relative to our momentum before we jump.

Points Earned: 1/1

Your Response: B

9. A 5 kg object is moving with a constant speed of 40 m/s along a smooth surface. The sum of the forces on the object is

A. 200 N. B. 49 N. C. zero. D. There is not enough information

Points Earned: 1/1

Your Response: C

10. The measure of an object's resistance to a change in its state of motion is the object's

A. weight. B. density. C. size. D. mass.

Points Earned: 1/1

Your Response: D

11. In order to determine the acceleration of an object, we need to consider

A. the object's mass. B. the object's velocity. C. all of the forces external to the object D. (A) and (C) but not (B) E. (A) and (B) and (C)

Points Earned: 1/1

Your Response: D

12. When driving down country roads, cars often run into little bugs flying around, which proceed to make a mess on the windshield of the car when the car runs into them. In these collisions, which experiences the greater force, the car or the bug?

A. The car. B. The bug. C. It depends on the speed of the car and bug. D. They each experience the same force.

Points Earned: 1/1

Your Response: D

13. In question above, which experiences the greater acceleration, the car or the bug?

A. The car. B. The bug. C. It depends on the speed of the car and bug. D. They each experience the same acceleration.

Points Earned: 1/1

Your Response: B

14. If you blow up a balloon, and then release it, the balloon will fly away as the air rushes out. This is an illustration of

A. Newton's First Law. B. Newton's Second Law. C. Newton's Third Law. D. Galileo's Law of Inertia.

Points Earned: 1/1

Your Response: C

15. When you sit on a chair, the net force on you

A. is zero. B. is up. C. is down. D. depends on your weight.

Points Earned: 1/1

Your Response: A

16. A force is a vector quantity because it has both __.

A. magnitude and direction. B. mass and acceleration. C. action and reaction counterparts.

Points Earned: 1/1

Your Response: A

17. Inertia is a measure of an object's _____.

A. weight. B. force. C. mass. D. gravity. E. center of mass.

Points Earned: 1/1

Your Response: C

18. If the net force on an object is directed due west, which way does the acceleration point?

A. due west B. due east C. West only if the velocity is west. D. It could be in any direction.

Points Earned: 1/1

Your Response: A

19. A kilogram is a measure of an object's

A. volume B. force C. mass D. weight

Points Earned: 1/1

Your Response: C

20. You push on an box sitting on the floor horizontally with a force of 15 Newtons and the box does not move. The force of friction on the box is

A. 0 Newtons B. 15 Newtons in the direction of your push C. 15 Newtons opposite to your push D. less that 15 Newtons.

Points Earned: 1/1

Your Response: C

21. Which of the following is a scalar?

A. velocity B. force C. acceleration

D. all of the above E. none of the above

Points Earned: 1/1

Your Response: E

22. An object of 2 kg mass, acted upon by a net force of 20 N, will experience what acceleration?

A. 5 m/s2 B. 10 m/s2 C. 7.5 m/s2 D. 12.4 m/s2

Points Earned: 1/1

Your Response: B

23. A box rests on a level table. Let W be the weight of the box, and N is the normal of the table on the box. In magnitude, W is opposite and ___ N, and the two forces ___ an action-reaction pair.

A. equals, are B. equals, are not C. is greater than, are D. is greater than, are not

Points Earned: 1/1

Your Response: A

24. A 2.0 kg object is acted on by a force F. the object is moving with acceleration of 10 m/s2 . Find F.

A. 0.2 N B. 5 N C. 12 N D. 20 N E. none of them

Points Earned: 1/1

Your Response: D

25. You jump off a truck and accelerate towards the surface of the Earth. Does the Earth accelerate towards you?

A. Yes, but the acceleration of the Earth is very small. B. No, the acceleration of the Earth is zero. C. Yes, Newton’s 3rd Law implies the accelerations are equal. D. can not be determined E. none of the above

Points Earned: 1/1

Your Response: A

26. All objects tend to maintain their state of motion because they have …

A. mass. B. weight. C. speed. D. acceleration. E. all of these.

Points Earned: 1/1

Your Response: A

27. If a 60 ton Patton tank collides with a little Honda Civic, which vehicle will experience the greater impact force?

A. The tank. B. The Civic. C. Both the same. D. Neither feels a force.

Points Earned: 1/1

Your Response: C

28. If a net force is acting on an object, then ______

A. The object is at rest. B. The object is moving with constant velocity. C. The object is being accelerated. D. The object is losing mass.

Points Earned: 1/1

Your Response: C

29. In Newtonian mechanics, ____ is the cause and _____ the effect.

A. acceleration . . . velocity B. force . . . acceleration C. acceleration . . . force D. force . . . velocity E. none of the above

Points Earned: 1/1

Your Response: B

30. Bill weighs 160 lb. He is standing on a bathroom scale inside an elevator. What is the reading on the scales if the elevator is accelerating downward?

A. 160 lb B. less than 160 lb C. greater than 160 lb

D. zero

Points Earned: 1/1

Your Response: B


Points Awarded 12

Points Missed 0

Percentage 100%

1. Team A beat team B in a game of Tug-O-War. We therefore know that if the winning team pulled on the rope with a force of 10000 N, the losing team pulled on the rope with a force of

A. less than 10,000 N B. 10,000 N C. more than 10,000 N D. need more info

Points Earned: 1/1

Correct Answer: A

Your Response: A

2. The measure of an object's resistance to a change in its state of motion is the object's

A. weight. B. density. C. size. D. mass.

Points Earned: 1/1

Correct Answer: D

Your Response: D

3. If a 60 ton Patton tank collides with a little Honda Civic, which vehicle will experience the greater impact force?

A. The tank. B. The Civic. C. Both the same.

D. Neither feels a force.

Points Earned: 1/1

Correct Answer: C

Your Response: C

4. Object A weighs 40 N on Earth, and object B weighs 40 N on the moon. The moon's gravity is one sixth of Earth's. Compare the masses of the objects.

A. A has 6 times the mass of b. B. B has 6 times the mass of a. C. A and B have equal mass. D. The situation as stated is impossible.

Points Earned: 1/1

Correct Answer: B

Your Response: B

5. A constant net force acts on an object. Describe the motion of the object.

A. Constant acceleration. B. Constant speed. C. Constant velocity. D. Increasing acceleration.

Points Earned: 1/1

Correct Answer: A

Your Response: A

6. A packing crate slides down an inclined ramp at constant velocity. Thus we can deduce that

A. a frictional force is acting on it. B. a net downward force is acting on it. C. it may be accelerating. D. it is not acted on by appreciable gravitational force.

Points Earned: 1/1

Correct Answer: A

Your Response: A

7. An object of 2 kg mass, acted upon by a net force of 20 N, will experience what acceleration?

A. 5 m/s2 B. 10 m/s2 C. 7.5 m/s2 D. 12.4 m/s2

Points Earned: 1/1

Correct Answer: B

Your Response: B

8.

A tugboat is used to nudge a large ocean liner into its appropriate berth; the mass of the tugboat is only 0.01 times the mass of the ocean liner. If, at a particular moment, the tugboat is exerting a force of 912,000 N on the ocean liner, what is the magnitude of the force being exerted by the ocean liner on the tugboat?

A. 0 N B. 9120 N C. 912,000 N D. 91,200,000 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

9. If an object accelerates at 5 m/s2 when acted upon by a 10 N force, what is its mass?

A. 0.5 kg B. 2 kg C. 5 kg D. 10 kg E. 50 kg

Points Earned: 1/1

Correct Answer: B

Your Response: B

10. A jumbo jet cruises at a constant velocity when the total thrust of the engines on the jet is 40,000 N. How much air resistance acts on the jet?

A. 80,000 N B. 60,000 N C. 40,000 N D. 20,000 N E. 0 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

11. Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue at 2.0 m/s2?

A. 3.0 N B. 5.0 N

C. 25 N D. 50 N

Points Earned: 1/1

Correct Answer: B

Your Response: B

12. A 7 kg bowling ball experiences a net force of 5 N. What will be its acceleration?

A. 35 m/s2 B. 7.0 m/s2 C. 5.0 m/s2 D. 0.71 m/s2

Points Earned: 1/1

Correct Answer: D

Your Response: D


Points Awarded 15

Points Missed 0

Percentage 100%

1. A crate is pulled across a horizontal floor by a rope tied to the crate. The rope makes an angle of 37 degrees with the horizontal. Find the frictional force If the tension in the rope is 10N and the crate moves with constant velocity.

A. 3.0 N B. 5.0 N C. 7.0 N D. 8.0 N E. none of them

Points Earned: 1/1

Your Response: D

2. A crate slides down a ramp making 35o with horizontal with constant speed. What is the coefficient of kinetic friction between the crate and the ramp?

A. 0.25 B. 0.45 C. 0.50 D. 0.60 E. 0.70

Points Earned: 1/1

Your Response: E

3. The coefficient of static friction between the tires of a car and asphalt is s = 0.77. What is the steepest angle of a slope, on which the car can be parked?

A. 22.5

B. 30

C. 38

D. 45

Points Earned: 1/1

Your Response: C

4. A 500 N weight is hung at the middle of a rope attached to two buildings at the same level. It breaks if the tension exceeds 1800 N. What is the minimum angle the rope can make with the horizontal?

A. 4

B. 8 C. 11

D. 18

Points Earned: 1/1

Your Response: B

5. Sam is using a rope to pull a box weighing 300 N across a floor with constant velocity. The rope makes an angle of 300 above the horizontal. If the tension in the rope is 100 N what is the normal force exerted by the floor on the box?

A. 300 N B. 290 N C. 270 N D. 250 N

Points Earned: 1/1

Your Response: D

6. A 5.0 kg block is pulled horizontally across a floor by a string attached to it with an acceleration of a 2 m/s2 k. What is the tension in the string if the coefficient of sliding kinetic friction between the block and floor 0.2?

A. 5.6 N B. 9.8 N C. 19.8 N

D. 28.9 N

Points Earned: 1/1

Your Response: C

7. A force of 250 N pushes a 50-kg box along a horizontal surface. The force is directed 300 below the horizontal. What is the acceleration of the box if the coefficient of kinetic friction between the box and the surface is 0.30?

A. 0.637 m/s2

B. 1.77 m/s2 C. 3.16 m/s2 D. 6.31 m/s2

Points Earned: 1/1

Your Response: A

8. The word "normal" in the phrase "normal force" indicates that

A. the force is exerted by a surface B. the force is exerted by an object C. the force exerted by a surface is parallel to itself D. the force exerted by a surface is perpendicular to itself

Points Earned: 1/1

Your Response: D

9. A 1.50 kg mass is acted upon by a force of 16.0 N applied at an angle of 600 above the horizontal. What is the acceleration of the mass?

A. 4.33 m/s2

B. 5.33 m/s2

C. 6.33 m/s2

D. 7.35 m/s2

Points Earned: 1/1

Your Response: B

10. A weight of 5000 N is suspended by two cables. The object is at rest. First cable is horizontal and the second makes an angle of 143o with the first cable Find the tension of the first cable.

A. 4000 N B. 6640 N C. 8310 N D. 3340 N

Points Earned: 1/1

Your Response: B

11. Two blocks with masses 2.00 kg and 4.00 kg are placed side-by-side on a frictionless horizontal surface. A horizontal force of magnitude of 5.20 N is applied to the 2.00 kg block perpendicular to its surface. What is the magnitude of the force on the 4.00 kg block?

A. 2.60 B. 3.11 C. 3.47 D. 3.89

Points Earned: 1/1

Your Response: C

12. A 43 kg child sits in a massless swing. With what horizontal force the seat must be pulled so that the ropes form an angle of 35o with respect to the vertical?

A. 300 N B. 320 N C. 340 N D. 360 N

Points Earned: 1/1

Your Response: A

13. A physics student holds a 2.40 kg block against a wall by pressing on it perpendicularly to the wall. Find the minimum force she must exert If the coefficient of static friction s=0.32.

A. 7.53 B. 73.5 C. 23.5 D. 235 E. not enough information

Points Earned: 1/1

Your Response: B

14. A pair of “fuzzy dice” hangs from a string attached to the rear view mirror of a race car moving with constant acceleration. Find the acceleration if the string makes a 70o angle with the vertical.

A. 22 m/s2

B. 27 m/s2

C. 33 m/s2

D. 35 m/s2

E. 39 m/s2

Points Earned: 1/1

Your Response: B

15. Two forces act on a 5 kg object. One force is 40 N and directed East. The other force is directed West. The acceleration of the object is 3 m/s2 West. What is the magnitude and direction of the second force?

A. 15 N West B. 55 N West C. 25 N East D. 55 N East

Points Earned: 1/1

Your Response: B


Points Awarded 12

Points Missed 1

Percentage 92%

1. A weight of 5000 N is suspended by two cables. The object is at rest. First cable is horizontal and the second makes an angle of 143o with the first cable Find the tension of the second cable..

A. 5000 N B. 6740 N C. 8310 N D. 9340 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

2. A 1 kg block starts sliding up a frictionless 300 inclined plane with an initial velocity of 4.00 m/s. How far does the block go up the ramp before stopping?

A. 1.56 m B. 1.63 m C. 1.79 m D. 2.16 m

Points Earned: 1/1

Correct Answer: B

Your Response: B

3. A 40-kg crate is being pulled across a floor by a rope which exerts a force of 10 N at an angle of 350 above the horizontal. Find the normal force exerted by the floor?

A. 17.1 N B. 15.7 N C. 387 N D. 398 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

4. A crate slides down a ramp making 35o with horizontal with constant speed. What is the coefficient of kinetic friction between the crate and the ramp?

A. 0.25 B. 0.45 C. 0.50 D. 0.60 E. 0.70

Points Earned: 1/1

Correct Answer: E

Your Response: E

5. A 5.0 kg block is pulled horizontally across a floor by a string attached to it with an acceleration of a 2 m/s2 k. What is the tension in the string if the coefficient of sliding kinetic friction between the block and floor 0.2?

A. 5.6 N B. 9.8 N C. 19.8 N D. 28.9 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

6. A pair of “fuzzy dice” hangs from a string attached to the rear view mirror of a race car moving with constant acceleration. Find the acceleration if the string makes a 70o angle with the vertical.

A. 22 m/s2

B. 27 m/s2

C. 33 m/s2

D. 35 m/s2

E. 39 m/s2

Points Earned: 1/1

Correct Answer: B

Your Response: B

7. Two horizontal forces act on a 5.0-kg mass. One force has a magnitude of 8.0 N and is directed due north. The second force toward the east has a magnitude of 6.0 N. What is the acceleration of the mass?

A. 1.6 m/s2 due north B. 1.2 m/s2 due east C. 2.0 m/s2 at 530 N of E D. 2.0 m/s2 at 53m E of N

Points Earned: 1/1

Correct Answer: C

Your Response: C

8. A mass is placed on a smooth inclined plane with an angle of 370 to the horizontal. If the inclined plane is 5.0-m long, how long does it take for the mass to reach the bottom of the inclined plane after it is released from rest?

A. 1.3 s B. 1.2 s C. 1.1 s D. 1.0 s

Points Earned: 0/1

Correct Answer: A

Your Response: B

9. A 250 kg crate is placed on an adjustable inclined plane. If the crate slides down the incline with an acceleration of 0.7 m/s2 when the incline angle is 25 o, then what should the incline angle be for the crate to slide down the plane at constant speed? (g = 9.8 m/s2)

A. 12 o B. 21 o

C. 25 o D. 29 o

Points Earned: 1/1

Correct Answer: B

Your Response: B

10. Anna pulls on a rope attached to a 124 kg log with a force of 50.0 N at an angle of 350 above the horizontal. The magnitude of the acceleration is _____ m/s.

A. 0.403 B. 2.48 C. 0.330 D. 0.231

Points Earned: 1/1

Correct Answer: C

Your Response: C

11. Two masses (3-kg and 5-kg) are attached by a string and passed over a frictionless pulley. Neglect the masses of the string and pulley. What will be the acceleration of the masses when released?

A. 3.92 m/s2

B. 9.8 m/s2 C. 2.45 m/s2

D. 6.53 m/s2

Points Earned: 1/1

Correct Answer: C

Your Response: C

12. A block of mass M slides down a frictionless plane inclined at an angle È with the horizontal. The normal reaction force exerted by the plane on the block is

A. Mg B. Mg sin C. Mg cos D. zero, since the plane is frictionless.

Points Earned: 1/1

Correct Answer: C

Your Response: C

13. If a box is slid at a constant speed up a frictionless slope, pulling parallel to the slope, the tension in the rope will be:

A. greater than the tension would be if the box were stationary. B. greater than the weight of the box.

C. equal to the weight of the box. D. less than the weight of the box.

Points Earned: 1/1

Correct Answer: D

Your Response: D


Points Awarded 26

Points Missed 1

Percentage 96%

1. A car is traveling at a constant speed of 22 m/s around a curve of radius 85 m. What is the the car's acceleration?

A. zero B. 22 m/s2 C. 9.8 m/s2

D. 5.7 m/s2

Points Earned: 1/1

Your Response: D

2. The earth rotates once in 24 hours about its axis. What is the rotational speed of the Earth?

A. (pi/24) rad/hourB. (pi/12) rad/hourC. (pi/6) rad/hourD. (pi/4) rad/hour

Points Earned: 1/1

Your Response: B

3. The maximum speed that a 2200 kg car can go around a level circular track of radius of 30.0

m without slipping if the coefficient of static friction between the tires and the road is 0.900 is

A. 10.2 m/s B. 16.3 m/s C. 27.0 m/s D. 66.0 m/s

Points Earned: 1/1

Your Response: B

4. A 0.30 kg rock is rotating in a vertical plane on a 0.25 m long string. At the top of the path, the velocity is 4.0 m/s. Find the tension in the string at that point.

A. 16.3 N B. 15.4 N C. 18 N D. 83 N

Points Earned: 1/1

Your Response: A

5. A 2000 kg roller coaster is at the top of a loop with a radius of 24 m. If its speed is 18 m/s at this point, what force does it exert on the track? (g = 9.8 m/s2)

A. 4.66*104 N B. 7.40*103 N C. 3.00*104 N D. 1.00*104 N

Points Earned: 1/1

Your Response: B

6. A 2.0-kg stone is swung swings in a vertical circle on end of a 1.0-m string. Find the tension of the string at the bottom point if the speed of the stone at this point is 4.0 m/s.

A. 0 B. 12 C. 20 D. 32 E. 52

Points Earned: 1/1

Your Response: E

7. A roller coaster loop has a radius of 12 m. What is the minimum speed the car must have at the top?

A. 6 m/s B. 11 m/s C. 13 m/s D. 15 m/s

Points Earned: 1/1

Your Response: B

8. A wheel of radius 50 cm rotates at angular velocity 4 rad/s. The linear velocity of the point on the rim of the wheel is

A. 1 m/s B. 2 m/s C. 3 m/s D. 4 m/s E. 5 m/s

Points Earned: 1/1

Your Response: B

9. What is the approximate angular speed of a wheel rotating at the rate of 5.0 rev/s?

A. 3.2 rad/s B. 1.6 rad/s C. 16 rad/s D. 31 rad/s

Points Earned: 1/1

Your Response: D

10. A helicopter has 3.0 m long rotor blades that are rotating at an angular speed of 63 rad/s. What is the tangential speed of each blade tip?

A. 99 m/s B. 190 m/s C. 21 m/s D. 66 m/s

Points Earned: 1/1

Your Response: B

11. The end of the cord on a weed cutter is 0.15 m in length. If the motor rotates at the rate of 126 rad/s, what is the tangential speed of the cord?

A. 628 m/s B. 25 m/s C. 19 m/s D. 63 m/s

Points Earned: 1/1

Your Response: C

12. A stone on the edge of the tire of a unicycle wheel with a radius of 0.25 m has a centripetal acceleration of 4.0 m/s2. What is the tire's angular speed?

A. 1.0 rad/s B. 2.0 rad/s C. 3.2 rad/s D. 4.0 rad/s

Points Earned: 1/1

Your Response: D

13. A lapidary plate at rest is turned on to cut a gemstone. The plate rotates until it reaches an angular speed of 12.0 rad/s in 4.0 s. What is the MAXIMUM centripetal acceleration experienced by a point 0.1 m from the center?

A. 0.45 m/s2

B. 7.2 m/s2 C. 14 m/s2 D. 29 m/s2

Points Earned: 1/1

Your Response: C

14. If the distance from the center of a merry-go-round to the edge is 1.2 m, what centripetal acceleration does a passenger experience when the merry-go-round rotates at an angular speed of 0.5 rad/s?

A. 1.7 m/s2

B. 0.9 m/s2

C. 0.3 m/s2

D. 0.6 m/s2

Points Earned: 1/1

Your Response: C

15. Consider a point on a bicycle wheel as the wheel turns about a fixed axis, neither speeding up nor slowing down. Compare the linear and angular velocities of the point.

A. Both are constant. B. Only the angular velocity is constant. C. Only the linear velocity is constant. D. Neither is constant.

Points Earned: 1/1

Your Response: B

16. The acceleration of an object undergoing uniform circular motion is constant in

A. magnitude only. B. direction only. C. both magnitude and direction. D. neither magnitude and direction.

Points Earned: 1/1

Your Response: A

17. Which of the following statements is true for a particle in uniform circular motion?

A. Its velocity and acceleration vectors are always parallel B. Its velocity and acceleration vectors are always perpendicular. C. Its acceleration vector is constant. D. Its velocity vector is constant.

Points Earned: 1/1

Your Response: B

18. The centripetal force on a car rounding a curve on a level road is provided by

A. gravity. B. friction between its tires and the road. C. the torque applied to its steering wheel. D. its brakes.

Points Earned: 1/1

Your Response: B

19. If we were to spin an object about our head by attaching it to string, and the string were to break when the object is directly in front of us, the object would

A. fly off in the direction it was traveling when the string broke. B. fly off in a straight line directly away from us. C. continue in a circular motion while falling to the ground. D. would drop to the ground directly in front of us.

Points Earned: 0/1

Your Response: B

20. A car travels in a circle with constant speed. The net force on the car is

A. zero because the car is not accelerating. B. directed towards the center of the curve. C. directed forward, in the direction of travel. D. none of these.

Points Earned: 1/1

Your Response: B

21. A motorcycle has a mass of 250 kg. It goes around a 13.7 m radius turn at 96.5 km/h.

What is the centripetal force on the motorcycle?

A. 719 N B. 2.95x103 N C. 1.31x104 N D. 4.31x104 N

Points Earned: 1/1

Your Response: C

22. An object moves in a circular path at a constant speed. Consider the direction of the object's velocity and acceleration vectors.

A. Both vectors point in the same direction. B. The vectors point in opposite directions. C. The vectors are perpendicular. D. The question is meaningless, since the acceleration is zero.

Points Earned: 1/1

Your Response: C

23. A toy car moves at the end of a string 1.60 m long in a circular path. If the breaking strength of the string is 36.0 N and the mass of the car is 1.95 kg, the maximum speed of the car is _____ m/s.

A. 7.83 B. 18.5 C. 29.5 D. 5.44

Points Earned: 1/1

Your Response: D

24. A 65.0 kg man runs at a constant speed 3.20 m/s around a circular track with a diameter of 240 m. The centripetal force necessary to do this is _____ N.

A. 5.55B. 1.78C. 34.6D. 82.9

Points Earned: 1/1

Your Response: A

25. The centripetal force necessary to cause a 2600 kg car traveling at a speed of 40.0 m/s to move around a circular track of radius of 35.0 m is _____ kN.

A. 104 B. 119 C. 204

D. 302

Points Earned: 1/1

Your Response: B

26. A car moves around a circular track with a constant speed. The direction of the acceleration is

A. in the direction of motion B. in the opposite direction of the motion C. radially outward D. radially inward

Points Earned: 1/1

Your Response: D

27. What centripetal force does an 80 kg passenger experience when seated 12 m from the center of a Ferris wheel whose linear speed is 6.00 m/s?

A. 484 N B. 720 N C. 914 N D. 240 N

Points Earned: 1/1

Your Response: D

Quiz 2-3

Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 4/7/2012 7:18:02 PM

Points Awarded 12

Points Missed 3

Percentage 80%

1. An object moves in a circular path at a constant speed. Consider the direction of the object's velocity and acceleration vectors.

A. Both vectors point in the same direction. B. The vectors point in opposite directions. C. The vectors are perpendicular. D. The question is meaningless, since the acceleration is zero.

Points Earned: 1/1

Correct Answer: C

Your Response: C

2. It is possible for an object to be apparently weightless when moving in a vertical circle.

A. True. B. False. C. There is not enough information.

Points Earned: 1/1

Correct Answer: A

Your Response: A

3. You’re on a diet. You step on a scale to determine your weight. As a result of the Earth’s rotation, the value read off the scale is

A. less than your true weight. B. greater than your true weight. C. is equal to your true weight only if you’re at the equator. D. is equal to your weight at the poles of the Earth. E. a and d are true F. b and c are true G. b and d are true

Points Earned: 1/1

Correct Answer: E

Your Response: E

4. Consider a point on a bicycle wheel as the wheel turns about a fixed axis, neither speeding up nor slowing down. Compare the linear and angular velocities of the point.

A. Both are constant. B. Only the angular velocity is constant. C. Only the linear velocity is constant. D. Neither is constant.

Points Earned: 1/1

Correct Answer: B

Your Response: B

5. If the magnitude of the velocity of an object moving in a circular path doubles, the centripetal acceleration is multiplied by

A. ¼ B. ½ C. 2 D. 4

Points Earned: 1/1

Correct Answer: D

Your Response: D

6. An object moves in a circle. If the mass is tripled, the speed halved and the radius unchanged then the centripetal force must change by a factor of

A. 3/2 B. 3/4 C. 9/4 D. 6 E. 12

Points Earned: 1/1

Correct Answer: B

Your Response: B

7. The Earth is 1.49 X 1011 m from the sun and its period of revolution is 1 year. What is the orbital acceleration of the Earth about the sun?

A. 18.6 m/s2 B. 5.88 X 1012 m/s2 C. 1.87 X 105 m/s2 D. 5.9 X 10-3 m/s2

Points Earned: 0/1

Correct Answer: D

Your Response: B

8. A stone is tied to the end of a string and is swung with constant speed around a horizontal circle with a radius of 1.5 m. If it makes two complete revolutions each second, its

acceleration is:

A. 0.24 m/s2 B. 2.4 m/s2 C. 24 m/s2 D. 240 m/s2 E. 2400 m/s2

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. In order to simulate weightlessness for astronauts in training, they are flown in a vertical circle. If the passengers are to experience weightlessness, how fast should an airplane be moving at the top of a vertical circle with a radius of 2500 m?

A. 157 m/s B. 314 m/s C. 255 m/s D. 510 m/s

Points Earned: 1/1

Correct Answer: A

Your Response: A

10. A helicopter has 3.0 m long rotor blades that are rotating at an angular speed of 63 rad/s. What is the tangential speed of each blade tip?

A. 99 m/s B. 190 m/s C. 21 m/s D. 66 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B

11. A person swings an iron ball in a vertical circle at the end of a string. At what point in the circle is the string most likely to break?

A. At the top of the circle. B. At the bottom of the circle. C. At the side of the circle going up. D. At the side of the circle going down.

Points Earned: 1/1

Correct Answer: B

Your Response: B

12. Various points on a rotating Ferris wheel have ______ linear velocities and _______ angular velocities.

A. equal, equal B. different, different C. equal, different D. different, equal

Points Earned: 0/1

Correct Answer: D

Your Response: A

13. A coin is fixed in place 11 cm from the axis of a rotating turntable. The angular speed of the turntable is increased and when it reaches 36 rev/min the coin slides off. What is the coefficient of static friction between the coin and the turntable?

A. 0.56 B. 0.32 C. 0.16 D. 0.11

Points Earned: 1/1

Correct Answer: C

Your Response: C

14. A 0.40 kg object attached to the end of a 0.50 m string rotates in a vertical circle. If the angular speed of the object at the bottom of the circle is 8.0 rad/s, what is the tension in the string at this point?

A. 10 N B. 11 N C. 13 N D. 17 N

Points Earned: 0/1

Correct Answer: D

Your Response: C

15. A 0.40 kg ball on a 0.50 m string rotates in a circular path in a vertical plane. If a constant angular speed of 8.0 rad/s is maintained, what is the tension in the string when the ball is at the top of the circle?

A. 9.0 N B. 11 N C. 13 N D. 10.0 N

Points Earned: 1/1

Correct Answer: A

Your Response: A


Points Awarded 16

Points Missed 1

Percentage 94%

1. Two bodies, masses m1 and m2, are at distance r from each other attract each other with force F. Find the gravitational force if the distance is doubled.

A. 2F B. F/2 C. F/4 D. 4F

Points Earned: 1/1

Your Response: C

2. The weight of a 0.5 kg object on the surface of Planet X is 20 N. If the radius of the planet is 4 X 106 m, what is its mass?

A. 3.4 X 1019 kg B. 2.6 X 1022 kg C. 9.6 X 1024 kg D. 2.3 X 1025 kg

Points Earned: 1/1

Your Response: C

3. Use Kepler's Law to find the time (in Earth’s years) for Mars to orbit the sun if the radius of Mars’ orbit 1.5 times the radius of Earth's orbit.

A. 1.8 B. 2.8 C. 3.4 D. 4.2

Points Earned: 1/1

Your Response: A

4. The mass of Planet W is 1/100 that of Earth and its radius is 1/4 that of Earth. If the weight of an object is 600 N on Earth, what would it weigh on this planet?

A. 24 N B. 48 N C. 96 N D. 192 N E. 600 N

Points Earned: 1/1

Your Response: C

5. The weight of an object at the surface of Earth is 90 N. What is its weight at a distance 2R from the surface of Earth?

A. 10 N B. 30 N C. 90 N D. 270 N E. 810 N

Points Earned: 1/1

Your Response: A

6. The periods of a satellite orbiting a planet does not depend on the

A. radius of the orbit B. mass of the planet C. mass of the satellite D. it depends on all of the above.

Points Earned: 1/1

Your Response: C

7. A 9.0 × 103 kg satellite orbits the earth at the distance of 2.56 × 107 m from Earth’s surface. What is its period?

A. 1.1× 10 4 s B. 4.1 × 10 4 s C. 5.7 × 10 4 s D. 1.5 × 10 5 s

Points Earned: 1/1

Your Response: C

8. Comets go faster when they approach the Sun. This is an example of

A. Newton's Law of Gravity B. Kepler's First Law C. Kepler's Second Law D. Kepler's Third Law.

Points Earned: 1/1

Your Response: C

9. Knowing the orbital period, this law can be used to find the average distance of a planet from the Sun,


Points Earned: 1/1

Your Response: D

10. The Earth moves around the Sun in an elliptical orbit. This is an example of


Points Earned: 1/1

Your Response: B

11. Which of the following statements about Newton’s Universal Law of Gravity is false?

A. The heavier mass exerts a force on the lighter mass that is equal but opposite to the force the lighter mass exerts on the heavier mass.

B. A heavy mass from far away can exert the same gravitational force on you as a light mass that is nearby.

C. Masses under the influence of the gravitational force accelerate towards each other at the rate of 6.67 x 10-11 m/s2.

D. All of the above are true.

Points Earned: 1/1

Your Response: C

12. Kepler's laws of planetary motion involved

A. a relationship between the radii of the planet's orbits and their orbital periods. B. the geometrical shape of the sun as viewed from the planet earth. C. a relationship between the speed of the planet and its distance from the sun. D. both (a) and (c) but not (b). E. (a) and (b) and (c).

Points Earned: 1/1

Your Response: D

13. When the distance between two stars decreases by half, the force between them

A. decreases by one-quarter B. decreases by one-half C. increases to twice as much D. increases to four times as much E. stays the same

Points Earned: 1/1

Your Response: D

14. A hypothetical planet has a mass of half of the mass of the earth and a radius of twice of that of the earth. What is the magnitude of the gravitational acceleration on the planet if the gravitational acceleration on the earth is 9.81 m/s2?

A. 1.22 m/s2

B. 2.54 m/s2

C. 4.88 m/s2

D. 6.78 m/s2

E. 9.81 m/s2

Points Earned: 0/1

Your Response: C

15. Based on Newton’s law of universal gravitation

A. The greater the masses of the two bodies, the greater the attractive force between them

B. The greater the distance between the centers of the masses, the weaker the attractive force between them

C. A and B D. None of the above

Points Earned: 1/1

Your Response: C

16. Ocean tides are the result of

A. The ocean being so big B. Water being so heavy C. Difference in forces exerted by the moon on different of the earth D. Whales running races with one another

Points Earned: 1/1

Your Response: C

17. A satellite's orbit is maintained by a

A. normal force. B. frictional force. C. centrifugal force. D. gravitational force.

Points Earned: 1/1

Your Response: D


Points Awarded 9

Points Missed 1

Percentage 90%

1. A hypothetical planet has a mass of half of the mass of the earth and a radius of twice of that of the earth. What is the magnitude of the gravitational acceleration on the planet if the gravitational acceleration on the earth is 9.81 m/s2?

A. 1.22 m/s2

B. 2.54 m/s2

C. 4.88 m/s2

D. 6.78 m/s2

E. 9.81 m/s2

Points Earned: 1/1

Your Response: A

2. Two identical masses are placed precisely 1 m apart from each other. The gravitational force each exerts on the other is exactly 1 N. What is each mass? (The value of the gravitational constant of the universe is 6.67 x 10-11 Nm2/kg2.)

A. 1.22 x 105 kg B. 1.50 x 1010 kg C. 7.50 x 109 kg D. 1 kg

Points Earned: 1/1

Your Response: A

3. Knowing the orbital period, this law can be used to find the average distance of a planet from the Sun,


Points Earned: 1/1

Your Response: D

4. An artificial Earth satellite in an elliptical orbit has its greatest centripetal acceleration when it is at what location?

A. nearest the Earth B. farthest from the Earth C. between Earth and moon D. between Earth and sun

Points Earned: 1/1

Your Response: A

5. The gravitational attractive force between two masses is F. If the masses are moved to half of their initial distance, what is the gravitational attractive force?

A. F/4 B. F/2 C. 2F D. 4F

Points Earned: 1/1

Your Response: D

6. The acceleration of gravity on the moon is one-sixth what it is on earth. The radius of the moon is one-fourth that of the earth. What is the moon's mass compared to the earth's?

A. 1/6 B. 1/16 C. 1/24 D. 1/96

Points Earned: 1/1

Your Response: D

7. The mass of Mars is 7*1023 kg and its radius is 3*106 m. What is the escape velocity from the planet assuming no atmosphere? (choose the closest answer)

A. 5700 m/s B. 5900 m/s C. 5100 m/s D. 4800 m/s E. 6300 m/s

Points Earned: 0/1

Your Response: C

8. Newton’s law of gravitation predicts what force between two football players each with a mass of 100 kg and separated by a distance of 10 m?

A. 9*10-7 B. 7*10-9 C. 7*10-11 D. 9*10-8

Points Earned: 1/1

Your Response: B

9. What is the gravitational force on a 70-kg person, due to the moon? The mass of the moon is 7.36X1022 kg and the distance to the moon is 3.82X108 m.

A. 0.24 N B. 0.024 N C. 0.0024 N D. 0.00024

Points Earned: 1/1

Your Response: C

10. The planet Pluto orbits at a distance of 5.91 × 1012 meters from the sun. The planet Earth orbits the sun at a distance of 1.5 × 1011 meters from the sun. Approximately how long does it take Pluto to orbit the sun? Hint: What is the definition of an astronomical unit (A.u.)?

A. 1.44 × 1019 years. B. 3.27 × 108 years C. 247 years D. 11.6 years

Points Earned: 1/1

Your Response: C

Self-Check 3-1Your response has been submitted successfully.

Points Awarded 20

Points Missed 1

Percentage 95%

1. If it takes 40 J to push a large box 4 m across a floor, what is the magnitude of the force on the box? The push is in the same direction as the velocity of the box.

A. 4 N B. 10 N C. 40 N D. 160 N E. none of the above

Points Earned: 1/1

Your Response: B

2. A 1500 kg car travels at a speed of 20 m/s. What is its kinetic energy?

A. 15.0 x 105 J B. 2.5 x 105 J C. 3.0 x 105 J D. 6.0 x 105 J

Points Earned: 1/1

Your Response: C

3. A block slides down an inclined plane. Which force does zero work?

A. the weight B. friction C. normal force D. all of the above E. none of the above

Points Earned: 1/1

Your Response: C

4. A loaded sledge weighs 5000 N. It is pulled on level snow by a horizontal force on it. The

coefficient of kinetic friction between sledge and snow is 0.05. How much work is done by the force if the sledge traveled 1000 m at constant speed?

A. 2.5 * 104 J B. 2.5 * 105 J C. 5.0 * 105 J D. 2.5 * 106 J E. 5.0 * 106 J

Points Earned: 1/1

Your Response: B

5. A 8000-N car is moving at 12 m/s along a horizontal road. The driver applies the breaks and the car skids to a stop. How much kinetic energy is lost?

A. 4.8 * 104 J B. 5.9 * 104 J C. 1.2 * 105 J D. 5.8 * 105 J E. 4.8 *106 J

Points Earned: 1/1

Your Response: B

6. The amount of work required to stop a truck is equal to the:

A. velocity of the truck B. kinetic energy of the truck C. mass of the truck times its acceleration D. mass of the truck times its velocity E. square of the velocity of the truck

Points Earned: 1/1

Your Response: B

7. A 5.0-kg brick is moving horizontally at 6.0 m/s. In order to change its speed to 10.0 m/s, the net work done on the brick must be:

A. 40 J B. 90 J C. 160 J D. 400 J E. 550 J

Points Earned: 1/1

Your Response: C

8. Which of the following has the largest kinetic energy?

A. Mass 3M and speed V B. Mass 3M and speed 2V C. Mass 2M and speed 3V D. Mass M and speed 4V

Points Earned: 1/1

Your Response: C

9. A 40 N box is pulled up an inclined plane at a constant velocity. If the plane is inclined at an angle of 37o to the horizontal and the box travels 5 m, what is the work done by the force of gravity?

A. 120 J B. 6 J C. 1180 J D. 200 J

Points Earned: 1/1

Your Response: A

10. The work done by the centripetal force acting on an object moving at a constant linear speed is

A. greater than zero since a force acts and the object moves. B. greater than zero since it takes energy to turn an object. C. equal to zero because the object has constant speed. D. equal to zero because the force and the displacement of the object are

perpendicular.

Points Earned: 1/1

Your Response: D

11. A block slides down a plane (there is friction). Which force does zero work?

A. the weight B. friction C. normal force D. all of the above

Points Earned: 1/1

Your Response: C

12. It takes 40 J to push a large box 4 m across a floor. Assuming that the push is in the same direction as the displacement, what is the size of the force on the box?

A. 4 N. B. 10 N. C. 40 N. D. 160 N.

E. none of these.

Points Earned: 1/1

Your Response: B

13. A constant force is applied to an object that causes a certain displacement. If the angle between the force and the displacement is 135o, the work done by this force is

A. positive B. negative C. 0 D. Not enough information is given to answer this question

Points Earned: 1/1

Your Response: B

14. A boy holds a 40-N weight at arm's length for 10 s. His arm is 1.5 m above the ground. The work done by the force of the boy on the weight while he is holding it is:

A. 0 B. 650 J C. 600 J D. 400 J E. 60 J

Points Earned: 1/1

Your Response: A

15. The work done by gravity during the descent of a projectile is:

A. positive B. negative C. zero D. depends for its sign on the direction of the y axis E. depends for its sign on the direction of both the x and y axes

Points Earned: 1/1

Your Response: A

16. A 10 lb weight is lifted 5 ft. A 20 lb weight is lifted 2.5 ft. Which lifting required the most work?

A. 20 lb weight B. 10 lb weight C. same work for each lifting D. not enough information is given to work the problem

Points Earned: 1/1

Your Response: C

17. A car moving with a kinetic energy of 43200 J slows to a kinetic energy of 23000 J in

a distance of 25.6 m. The magnitude of the force acting on the car is _____ N.

A. 789 B. 2590 C. 1800 D. 1200

Points Earned: 0/1

Your Response: B

18. A boy pushes a sled with a force of 50.0 N directed parallel to the ground for a distance of 12.0 m in the direction of motion. If the initial kinetic energy of the sled was 400 J, then the final kinetic energy is _____ J.

A. 400 B. 600 C. 1000 D. 200

Points Earned: 1/1

Your Response: C

19. The amount of work required to stop a moving object is equal to the:

A. velocity of the object B. kinetic energy of the object C. mass of the object times its velocity D. mass of the object times its acceleration E. square of the velocity of the object

Points Earned: 1/1

Your Response: B

20. An object that has kinetic energy must be

A. falling. B. moving. C. at an elevated position. D. at rest. E. none of these.

Points Earned: 1/1

Your Response: B

21. The net or total work necessary to bring an object from zero velocity to its present nonzero velocity is equal to the _________ of the object.

A. kinetic energy B. potential energy

C. momentum D. force E. impulse

Points Earned: 1/1

Your Response: A


Points Awarded 16

Points Missed 1

Percentage 94%

1. John pulls a sled on a frictionless surface with a force of 60 N at an angle of 37o above the horizontal. If he pulls it a distance of 12 m, the work he does is

A. 185 J B. 433 J C. 575 J

D. 720 J

Points Earned: 1/1

Correct Answer: C

Your Response: C

2. A 6000N crate is pulled across an icy surface. The coefficient of kinetic friction is 0.05. The work done in pulling the crate 1000 m at constant velocity is:

A. 3.1*104 J B. 1.5*105 J C. 3.0*105 J D. 2.9 *106 J E. 6.0 *106 J

Points Earned: 1/1

Correct Answer: C

Your Response: C

3. If the work done on a particle is zero, then

A. the net force is zero B. the displacement is zero C. the acceleration is zero D. all of the above are possible

Points Earned: 1/1

Correct Answer: D

Your Response: D

4. A force does work on an object if a component of the force

A. is perpendicular to the displacement of the object. B. is parallel to the displacement of the object. C. perpendicular to the displacement of the object moves the object along a path that returns

the object to its starting position. D. parallel to the displacement of the object moves the object along a path that returns the

object to its starting position.

Points Earned: 1/1

Correct Answer: B

Your Response: B

5. A boy holds a 40-N weight at arm's length for 10 s. His arm is 1.5 m above the ground. The work done by the force of the boy on the weight while he is holding it is:

A. 0 B. 650 J C. 600 J

D. 400 J E. 60 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

6. Suppose that the Earth’s gravitational pull on an orbiting satellite is 100 N. If the satellite is in a circular orbit of radius 10,000 m, how much work does the Earth’s pull of gravity do in one revolution?

A. 6.28 MJ B. 1.00 MJ C. 5.34 MJ D. 0 MJ E. not enough information is given

Points Earned: 0/1

Correct Answer: D

Your Response: C

7. The net or total work necessary to bring an object from zero velocity to its present nonzero velocity is equal to the of the object.

A. kinetic energy B. potential energy C. momentum D. force E. impulse

Points Earned: 1/1

Correct Answer: A

Your Response: A

8. How much work is done on a 50-N rock that you lift 10 m?

A. 500 J B. 50 J C. 10 J D. 5 J E. 0 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

9. A horizontal force of 200 N is applied to move a 55 kg cart across a 10 m level surface. What work is done by the 200 N force?

A. 4000 J B. 5400 J C. 2000 J D. 2700 J

Points Earned: 1/1

Correct Answer: C

Your Response: C

10.

A 102 kg man climbs a 5 m high staircase at constant speed. How much work does he do? (acceleration due to gravity = g = 9.8 m/s2)

A. 510 J B. 49 J C. 4998 J D. 2499 J

Points Earned: 1/1

Correct Answer: C

Your Response: C

11. I use a motor to lift a 60 kg crate to a height of 15 meters off the ground. Assuming that it takes 45 seconds to lift the craft, how much power must the motor provide?

A. 20 W B. 180 W C. 196.2 W D. 8.83 kW

e.40.5 kW

Points Earned: 1/1

Correct Answer: C

Your Response: C

12. An automobile delivers 30 hp to its wheels when moving at a constant speed of 22 m/s. What is the resistance force on the automobile at this speed? (1 hp = 746 watts)

A. 18.6 x 103 N B. 4.1 x 105 N C. 1020 N D. 848 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

13. Do 100 J of work in 50 s and your power output is

A. 1/4 W. B. 1/2 W. C. 2 W. D. 4 W. E. more than 4 W.

Points Earned: 1/1

Correct Answer: C

Your Response: C

14. A 8000-N car is moving at 12 m/s along a horizontal road. The driver applies the breaks and the car skids to a stop. How much kinetic energy is lost?

A. 4.8 * 104 J B. 5.9 * 104 J C. 1.2 * 105 J D. 5.8 * 105 J E. 4.8 * 106 J

Points Earned: 1/1

Correct Answer: B

Your Response: B

15. How much work could be performed by a 619-kg object traveling horizontally at a speed of 32.5 m/s?

A. 327,000 J B. 654,000 J C. 197,000 J D. 0 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

16. The work done in lifting 60 kg of bricks to a height of 30 m on a building under construction is

A. 180 J B. 1800 J C. 1764 J D. 17640 J

Points Earned: 1/1

Correct Answer: D

Your Response: D

17. If both the mass and the velocity of a ball are tripled, the kinetic energy of the ball is increased by a factor of

A. 3. B. 6. C. 9. D. 27.

Points Earned: 1/1

Correct Answer: D

Your Response: DImportant links- Report


Points Awarded 10

Points Missed 3

Percentage 77%

1. A fighter jet of mass 9600 kg is moving at a speed of 72 m/s. If its total energy is 2.60 x 108 J, how high from the ground level is it?

A. 2500 m B. 2230 m C. 2760 m D. 3028 m

Points Earned: 0/1

Correct Answer: A

Your Response: C

2. Which of the following is associated with an object due to its position?

A. potential energy B. mechanical energy C. total energy D. kinetic energy

Points Earned: 1/1

Correct Answer: A

Your Response: A

3. A 40.0 N crate is pulled up a 5.0 m inclined plane. The angle of inclination of the plane to horizontal is 37o. If there is a constant force of friction of 10.0 N between the crate and the surface, what is the net gain in potential energy by the crate?

A. 120 J B. –120 J C. 210 J D. –210 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

4. A n 80-N crate is pushed a distance of 5.0 m upward along a smooth incline that makes an angle of 30 o with the horizontal. The force pushing the crate is parallel to the slope. If the speed of the crate increases at a rate of 1.5 m/s2, find the work done by the force:

A. 200 J B. 1 J C. 140 J D. 200 J E. 260 J

Points Earned: 0/1

Correct Answer: E

Your Response: D

5. Potential energy is energy associated with

A. motion B. position C. mass D. temperature

Points Earned: 1/1

Correct Answer: B

Your Response: B

6. A 2000-kg ore car rolls 50 meters down a smooth 10 o incline. There is a horizontal spring at the end of the incline designed to stop the car in case of break failure. What is the force constant of the spring if it would compress by 1 m to stop the ore car?

A. 340.3 kN/m B. 680.7 kN/m C. 980.0 kN/m D. 1960.0 kN/m

Points Earned: 1/1

Correct Answer: A

Your Response: A

7. Suppose a 0.3 kg mass on a spring that has been compressed 0.10 m has elastic potential energy of 1 J. What is the spring constant?

A. 10 N/m B. 20 N/m C. 200 N/m D. 300 N/m

Points Earned: 1/1

Correct Answer: C

Your Response: C

8. Three climbers, A, B, and C all climb the same mountain, starting from the same point. Each walks at the same rate during the entire climb, but each takes a different path. Neglect any effects of friction. Climber A picks a path that requires two hours to complete, B’s path requires 3 hours, and C’s path requires 4 hours. Which climber did more work?

A. A B. B C. C D. They all did the same amount of work.

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. A feather and a brick are dropped by a person standing on the Moon. At any given instant during the fall, they have equal

A. forces. B. kinetic energies. C. accelerations. D. gravitational potential energies.

Points Earned: 1/1

Correct Answer: C

Your Response: C

10. I drop a 60 g golfball from 2 m high. It rebounds to 1.5 m. How much energy is lost?

A. 0.29 J B. 0.5 J C. 0.88 J D. 1 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

11. Which of the following statements is false for an object tossed straight up and allowed to fall back down (ignore air resistance)?

A. The acceleration of the object is constant. B. The total mechanical energy of the object is always constant. C. The object never has a velocity equal to zero. D. The more massive the object is, the more mechanical energy it has.

Points Earned: 0/1

Correct Answer: C

Your Response: A

12. A change in the gravitational potential energy of an object

A. is always positive B. depends on the reference point where the potential energy is zero C. depends on the path the object takes between the initial and final positions D. depends only on the initial and final positions

Points Earned: 1/1

Correct Answer: D

Your Response: D

13. A force of 30.0 N is required to stretch a spring by 0.20 m. What work is done in stretching a spring from 0 to 0.40 m?

A. 12.0 J B. 6.00 J C. 3.00 J D. 1.50 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

uiz 3-2Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 4/8/2012 9:31:54 PM

Points Awarded 10

Points Missed 3

Percentage 77%

1. Select the best answer to the following question:Can potential energy of a system be negative?

A. Yes, as long as the total energy is positive. B. Yes, since the choice of the zero of potential energy is arbitrary. C. No, because the kinetic energy of a system must equal its potential energy. D. No, because this would have no physical meaning.

Points Earned: 1/1

Correct Answer: B

Your Response: B

2. Work done by STATIC FRICTION is always:

A. negative B. positive C. along the surface D. zero

Points Earned: 1/1

Correct Answer: D

Your Response: D

3. Which of the following is associated with an object due to its position?

A. potential energy B. mechanical energy C. total energy D. kinetic energy

Points Earned: 1/1

Correct Answer: A

Your Response: A

4. Which of the following energy forms is associated with an object in motion?

A. potential energy B. elastic potential energy C. nonmechanical energy D. kinetic energy

Points Earned: 1/1

Correct Answer: D

Your Response: D

5. I drop a 60 g golfball from 2 m high. It rebounds to 1.5 m. How much energy is lost?

A. 0.29 J

B. 0.5 J C. 0.88 J D. 1 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

6. Which of the following is that form of energy associated with an object's motion?

A. potential B. thermal C. bio-chemical D. kinetic

Points Earned: 1/1

Correct Answer: D

Your Response: D

7. A force of 30.0 N is required to stretch a spring by 0.20 m. What work is done in stretching a spring from 0 to 0.40 m?

A. 12.0 J B. 6.00 J C. 3.00 J D. 1.50 J

Points Earned: 1/1

Correct Answer: A

Your Response: A

8. A 60 g golf ball is dropped from a height of 2 m and rebounds to 1.5 m. How much energy is lost?

A. 0.29 J B. 0.5 J C. 0.88 J D. 1J

Points Earned: 1/1

Correct Answer: A

Your Response: A

9. A feather and a brick are dropped by a person standing on the Moon. At any given instant during the fall, they have equal

A. forces. B. kinetic energies.

C. accelerations. D. gravitational potential energies.

Points Earned: 0/1

Correct Answer: C

Your Response: B

10. A spring with constant k = 120 N/m is compressed by 36 cm. How much potential energy does it store?

A. 7.78 J B. 15.55 J C. 43.2 J D. 124.7 J E. 333 J

Points Earned: 0/1

Correct Answer: A

Your Response: B

11. A change in the gravitational potential energy of an object

A. is always positive B. depends on the reference point where the potential energy is zero C. depends on the path the object takes between the initial and final positions D. depends only on the initial and final positions

Points Earned: 1/1

Correct Answer: D

Your Response: D

12. A body can have negative potential energy when

A. potential energy is relative and can be negative at any time. B. it is falling. C. only if its in a hole. D. never.

Points Earned: 0/1

Correct Answer: A

Your Response: D

13. An 80,000 kg plane is flying at 900 km/h at a height of 10 kilometers. What is its total mechanical energy?

A. 250 MJ B. 478 MJ C. 773 MJ

D. 10,340 MJ

Points Earned: 1/1

Correct Answer: D

Your Response: D


Points Awarded 22

Points Missed 0

Percentage 100%

1. Ruth is moving a heavy box a distance of 14.0 m across a floor of her bedroom. If she does 9000 J of work in 3.00s, her power is _____.

A. 3000 W B. 12000 W C. 149 W D. 1500 W

Points Earned: 1/1

Your Response: A

2. The rate at which work is done is equivalent to

A. increase in potential energy B. thermal energy C. potential energy D. power

Points Earned: 1/1

Your Response: D

3. A pulley-cable system on a construction site lifts a 20,000 N concrete block to a height of 40 m. If this takes 2 min., what is the power of the pulley-cable system?

A. 6.7 kW B. 3.3 kW C. 13.3 kW D. 400 kW

Points Earned: 1/1

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Your Response: A

4. A jet engine is moving an airplane forward at a speed of 900 km/hr. If the thrust of the engine is 105 N, What is the power developed by the engine?

A. 5 MW B. 10 MW C. 25 MW D. 50 MW

Points Earned: 1/1

Your Response: C

5. For safety reasons, the speed of a child at the bottom of a playground slide cannot exceed 6.0 m/s. What is the maximum height of the slide ?

A. 1.8 m B. 2.9 m C. 3.2 m D. 4.5 m

Points Earned: 1/1

Your Response: A

6. Sarah and her bicycle have a total mass of 40 kg. Her speed at the top of a 10 m high and 100m long hill is 5 m/s. If the force of friction on her way down is 20 N, at what speed she reaches the bottom?

A. 5 m/s B. 10 m/s C. 11 m/s D. She stops before she reaches the bottom.

Points Earned: 1/1

Your Response: C

7. A boy on a roof throws one ball downward and an identical ball upward. The ball thrown downward hits the ground with 100 J of kinetic energy. If both balls are thrown at the same speed and there is no air friction, what is the kinetic energy of the second just before it hits the ground?

A. 100 J B. 200 J C. Less than 100 J D. More than 200 J E. none of the above

Points Earned: 1/1

Your Response: A

8. A 500 kg roller coaster car crests a 20m high hill at a speed of 10 m/s. It then rolls down the

other side, all the way to ground level, and climbs a second hill. What is the speed of the car when it is 10 m up the second hill?

A. 15.3 m/s B. 17.2 m/s C. 8.9 m/s D. 19.7 m/s

Points Earned: 1/1

Your Response: B

9. A 6.00 kg block slides down a 3.40 m long inclined plane. The speed of the block at the bottom is 5.40 m/s. If the height of the plane is 2.00 m, what is the work done by friction?

A. -118 J B. -30.1 J C. -85.5 J D. -8.85 J

Points Earned: 1/1

Your Response: B

10. An object is shot upward at 34.3 m/s. How high does it go?

A. 60.0 m B. 180 m C. 103 m D. 1.75 m

Points Earned: 1/1

Your Response: A

11. A ball is released from a point above the Earth with an initial potential energy of 1000 J. If air resistance is not negligible, then its kinetic energy when it hits the ground will be

A. 1000 J B. less than 1000 J C. more than 1000 J D. no conclusions can be drawn

Points Earned: 1/1

Your Response: B

12. Energy cannot be

A. conserved B. created C. transferred

D. in more than one form

Points Earned: 1/1

Your Response: B

13. Which one of the following energy transformations takes place during friction?

A. Chemical energy is converted into Radiant energy. B. Thermal energy is converted into Mechanical energy. C. Mechanical energy is converted into Thermal energy. D. Chemical energy is converted into Potential energy.

Points Earned: 1/1

Your Response: C

14. A 2 kg ball which originally has zero kinetic and potential energy is dropped into a well which is 10 m deep. Just before the ball hits the bottom, the sum of its kinetic and potential energy is

A. 0 B. 196 J C. -196 J D. 392 J

Points Earned: 1/1

Your Response: A

15. Two blocks are released from the top of a building. One falls straight down while the other slides down a smooth ramp. If all friction is ignored, which one is moving faster when it reaches the bottom?

A. The block that went straight down. B. The block that went down the ramp. C. They both will have the same speed. D. Insufficient information to work the problem.

Points Earned: 1/1

Your Response: C

16. An arrow, shot straight up from a crossbow has an initial velocity of 50 m/s. Ignore energy lost to air friction. How high will the arrow rise?

A. 49 m B. 62.4 m C. 98 m D. 127.5 m

Points Earned: 1/1

Your Response: D

17. King Kong falls from the top of the Empire State Building, through the air (air friction is present), to the ground below. How does his kinetic energy (K) just before striking the ground compare to his potential energy (U) at the top of the building?

A. K is equal to U. B. K is greater than U. C. K is less than U. D. It is impossible to tell.

Points Earned: 1/1

Your Response: C

18. When a car is braked to a stop, its kinetic energy is transformed to

A. stopping energy. B. potential energy. C. heat energy. D. energy of rest.

Points Earned: 1/1

Your Response: C

19. The average power needed to raise a 5.00 kg mass a distance of 20.0 m in a time of 5.00 s is _____ W.

A. 98.0 B. 196 C. 980 D. 786

Points Earned: 1/1

Your Response: B

20. Power is the rate of change of _____ with respect to time.

A. position B. velocity C. energy D. mass

Points Earned: 1/1

Your Response: C

21. An automobile delivers 30 hp to its wheels when moving at a constant speed of 22 m/s. What is the resistance force on the automobile at this speed? (1 hp = 746 watts)

A. 18.6 x 103 N B. 4.1 x 105 N C. 1020 N

D. 848 N

Points Earned: 1/1

Your Response: C

22. How much power is required to do 100 J of work on an object in 2 seconds?

A. 200 W B. 100 W C. 50 W D. 2 W E. 0 W

Points Earned: 1/1

Your Response: C


Points Awarded 10

Points Missed 1

Percentage 91%

1. A roller coater car starts out at rest at the top of the first hill and reaches speed of 10 m/s at the bottom of the hill. What is its speed when it is half-way down? Assume that the track is frictionless.

A. 5.0 m/s

B. 7.1 m/s

C. 6.3 m/s

D. 20 m/s

E. none of them

Points Earned: 1/1

Your Response: B

2. A pole vaulter clears 6.00 m. What is his velocity just before landing?

A. 2.70 m/s

B. 5.40 m/s

C. 10.8 m/s

D. 21.6 m/s

Points Earned: 1/1

Your Response: C

3. A person on a roof throws one ball downward and an identical ball upward at the same speed. The ball thrown downward hits the ground with 100 J of kinetic energy. Ignoring air friction, with how much kinetic energy does the second ball hit the ground?

A. 100 J

B. 200 J

C. Less than 100 J

D. More than 200 J

E. none of the above

Points Earned: 1/1

Your Response: A

4. A ball is released from a point above the Earth with an initial potential energy of 1000 J. If air resistance is not negligible, then its kinetic energy when it hits the ground will be

A. 1000 J

B. less than 1000 J

C. more than 1000 J

D. no conclusions can be drawn

Points Earned: 1/1

Your Response: B

5. Two blocks are released from the top of a building. One falls straight down while the other slides down a smooth ramp. If all friction is ignored, which one is moving faster when it reaches the bottom?

A. The block that went straight down.

B. The block that went down the ramp.

C. They both will have the same speed.

D. Insufficient information to work the problem.

Points Earned: 1/1

Your Response: C

6. The amount of energy in the universe today is

A. always decreasing.

B. always increasing.

C. always constant.

D. always changing.

Points Earned: 1/1

Your Response: C

7. Sarah and her bicycle have a total mass of 40 kg. Her speed at the top of a 10 m high and 100m long hill is 5 m/s. If the force of friction on her way down is 20 N, at what speed she reaches the bottom?

A. 5 m/s

B. 10 m/s

C. 11 m/s

D. She stops before she reaches the bottom.

Points Earned: 1/1

Your Response: C

8. A 1.5 kg object falls from a height of 2.0 m onto a spring scale with a spring constant of 1.5x105 N/m. What is the reading on the scale at its greatest compression is?

A. 15 N

B. 30 N

C. 1.5x103 N

D. 2.1x103 N

E. 3.0x103 N

Points Earned: 1/1

Your Response: E

9. A simple pendulum, 2.0 m in length, is released with a push when the support string is at an angle of 25 o from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, what is its speed at the bottom of the swing? (g = 9.8 m/s2)

A. 2.3 m/s

B. 2.6 m/s

C. 2.0 m/s

D. 0.5 m/s

Points Earned: 0/1

Your Response: B

10. An ore car of mass 4000 kg rolls downhill on tracks from a mine. At the end of the tracks, at 10 m elevation lower is a spring with k = 400,000 N/m. How much is the spring compressed in

stopping the ore car? Ignore friction.

A. 0.14 m

B. 0.56 m

C. 1.40 m

D. 1.96 m

Points Earned: 1/1

Your Response: C

11. A pole vaulter clears 6 m. With what velocity does he strike the mat in the landing area?

A. 2.7 m/s

B. 5.4 m/s

C. 10.8 m/s

D. 21.6 m/s

Points Earned: 1/1

Your Response: C

Important links- Report an Error -~- Jeff


http://www.jefferson.k12.ky.us/

http://jcpseschool.jefferson.kyschools.us/section/content/default.asp?WCI=pgDisplay_Form&WCE=take&WCU=CRSCNT&ENTRY_ID=14DFCE32821C4EB084BB7C90EA03DE1B

Points Awarded 9

Points Missed 2

Percentage 82%

1. The more powerful the motor is, the

A. longer the time interval for doing the work is. B. shorter the time interval for doing the work is. C. greater the ability to do the work is. D. shorter the workload is.

Points Earned: 1/1

Your Response: B

2. A ball thrown vertically upward has an initial potential energy of 500 J and an initial kinetic energy of 1000 J. At the top of its trajectory its total energy is ___ J.

A. 500 B. 1000 C. 1500 D. -50

Points Earned: 1/1

Your Response: C

3. The rate at which work is done is equivalent to

A. increase in potential energy B. thermal energy C. potential energy D. power

Points Earned: 1/1

Your Response: D

4. A person on a roof throws one ball downward and an identical ball upward at the same speed. The ball thrown downward hits the ground with 100 J of kinetic energy. Ignoring air friction, with how much kinetic energy does the second ball hit the ground?

A. 100 J B. 200 J C. Less than 100 J D. More than 200 J E. none of the above

Points Earned: 0/1

Your Response: C

5. Which one of the following is always conserved?

A. power B. kinetic energy C. mechanical energy D. total energy in the universe

Points Earned: 1/1

Your Response: D

6. Wanda claims that she has invented a machine that will allow a force of 100 N to be exerted, when the operator exerts only 2 N on the machine. This machine violates

A. conservation of energy B. conservation of momentum C. no physical law

Points Earned: 0/1

Your Response: A

7. A rubber ball dropped on the floor. The rebound speed is one-half the speed it had just before hitting the floor. It will rise to ________ of the original height from which it was dropped.

A. 1/8 B. 1/6 C. 1/5 D. 1/4 E. 1/3 F. 1/2

Points Earned: 1/1

Your Response: D

8. An automobile of mass 2000 kg moving at 30 m/s, is braked suddenly, with a constant braking force of 10,000 N. How far does the car travel before stopping?

A. 45 m B. 90 m C. 135 m D. 180 m

Points Earned: 1/1

Your Response: B

9. A ball thrown vertically upward has an initial potential energy of 500 J and an initial kinetic energy of 1000 J. At the top of its trajectory its total energy is _____ J.

A. 500 B. 1000

C. 1500 D. -50

Points Earned: 1/1

Your Response: C

10. A 20 N crate starting at rest slides down a rough 3 m long ramp, inclined at 30o with the horizontal. The force of friction between crate and ramp is 6 N. The crate, with the mass of approximately 2 kg, will have what velocity at the bottom of the incline?

A. 0.5 m/s B. 1.4 m/s C. 2.8 m/s D. 3.4 m/s

Points Earned: 1/1

Your Response: D

11. An arrow, shot straight up from a crossbow has an initial velocity of 50 m/s. Ignore energy lost to air friction. How high will the arrow rise?

A. 49 m B. 62.4 m C. 98 m D. 127.5 m

Points Earned: 1/1

Your Response: D


Points Awarded 21

Points Missed 3

Percentage 88%

1. Bumper protects a car during a collision because it

A. increases the time of impact

B. decreases the time of impact

C. increases the force of impact

D. increases kinetic energy transfer

Points Earned: 1/1

Your Response: A

2. If two objects have the same momentum, then

A. the object with the greater mass will have the smaller velocity

B. the object with the greater mass will have the larger velocity

C. both objects have the same velocity

D. both objects have only the same speed

Points Earned: 0/1

Your Response: D

3. A 3-kg ball is rolling at a speed of 6 m/s. What is the magnitude of the momentum of the ball?

A. 6 m/s

B. 18 kg.m/s

C. 18 m/s

D. 6 kg.m/s

Points Earned: 1/1

Your Response: B

4. A brick falls to the ground. If the time for the collision of the brick and the ground is increased by a factor of 4, the force of the collision with the ground will change by a factor of

A. 4

B. 16

C. 1/4

D. 1/16

Points Earned: 1/1

Your Response: C

5. A 0.30 kg ball is dropped onto a concrete driveway. The ball's velocity before impact is 4.5 m/s, and after impact is 4.2 m/s. What is the change in the ball's momentum?

A. 0.09 kg-m/s

B. 2.6 kg-m/s

C. 4.0 kg-m/s

D. 116 kg-m/s

Points Earned: 1/1

Your Response: B

6. What is the speed of a 0.145 kg object moving with a momentum of 5.80 Ns?

A. 0.841 m/s

B. 1.19 m/s

C. 40.0 m/s

D. 36.0 m/s

Points Earned: 1/1

Your Response: C

7. Which is a vector?

A. linear momentum

B. impulse

C. neither a nor b

D. both a and b

Points Earned: 1/1

Your Response: D

8. A 1.5 kg ball falls onto a floor. Just before it strikes the floor, its velocity is 12 m/s. The ball bounces up with a velocity of 10 m/s. Find the impulse on the ball.

A. 3 N-s

B. 15 N-s

C. 18 N-s

D. 33 N-s

Points Earned: 1/1

Your Response: D

9. A soccer player kicks a soccer ball initially at rest setting it in motion at a velocity of 30 m/. If the ball has a mass of 0.5 kg and the time of contact is 0.025 s, what is the force exerted on player’s foot?

A. 188 N

B. 375 N

C. 600 N

D. 900 N

Points Earned: 1/1

Your Response: C

10. A 2 kg ball moving at 3 m/s hits a wall and bounces off. Immediately after the collision, it moves at 3 m/s in the opposite direction.What is the change in the object’s momentum?

A. + 12 kg m/s

B. -12 kg m/s

C. 0 kg m/s

D. +6 kg m/s

E. -6 kg m/s

F. More than one of the above is possible

G. None of the above is correct

Points Earned: 1/1

Your Response: F

11. A piece of putty and a tennis ball of equal mass are thrown against a wall with the same speed. If the tennis ball bounces off with the same speed but the putty sticks to the wall, then

A. the golf ball undergoes the greatest change of momentum

B. the putty undergoes the greatest change of momentum

C. the change in momentum for each is the same

D. the change depends on the angle of impact

Points Earned: 1/1

Your Response: A

12. It is impossible for an object to have zero momentum if it

A. has acceleration

B. has mass

C. has velocity

D. has potential energy

Points Earned: 1/1

Your Response: C

13. The magnitude of the force necessary to change the momentum of a particle from 10.0 Ns to 50.0 Ns in 12.0 s is _____ N.

A. 3.33

B. 44.0

C. 4.16

D. 720

Points Earned: 1/1

Your Response: A

14. A baseball moving with an initial momentum of 4.35 Ns, strikes a wall and rebounds with a momentum of -3.72 Ns. If the collision lasted for 0.020 s, then the magnitude of the force acting on the ball is _____ N.

A. 406

B. 31.5

C. 315

D. 127

Points Earned: 0/1

Your Response: B

15. A karate-master strikes a board with an initial velocity of 10 m/s, decreasing to 1 m/s as his hand passes through the board. If the time-of-contact with the board is 0.002 s, and the mass of the coordinated hand and arm is 1 kg, what is the force exerted on the board?

A. 1000 N

B. 1800 N

C. 2700 N

D. 4500 N

Points Earned: 1/1

Your Response: D

16. A baseball of mass 0.145 kg, moving at 55 m/s, is caught by a catcher during a time of 0.2 second. What is the average force felt by the catcher?

A. 40 N

B. 8 N

C. 1.6 N

D. 55 N

Points Earned: 1/1

Your Response: A

17. Which has more momentum, a 50 ton earth-moving dump truck moving at 25 mph, or a 10 ton tractor-trailer moving at 75 mph?

A. 50 ton truck.

B. 10 ton tractor.

C. Both the same.

D. Not enough information.

Points Earned: 1/1

Your Response: A

18. Which of the following undergoes the greatest change in momentum?

A. A baseball that is caught.

B. A baseball that is thrown.

C. A baseball that is caught and thrown back with the same speed.

D. They all have the same impulse.

Points Earned: 1/1

Your Response: C

19. Which of the following has the greatest momentum?

A. truck with a mass of 2250 kg moving at a velocity of 25 m/s

B. car with a mass of 1210 kg moving at a velocity of 51 m/s

C. truck with a mass of 6120 kg moving at a velocity of 10 m/s

D. car with a mass of 1540 kg moving at a velocity of 38 m/s

Points Earned: 1/1

Your Response: B

20. When comparing the momentum of two moving objects, which of the following is correct?

A. The object with the higher velocity will have less momentum if the masses are equal.

B. The more massive object will have less momentum if its velocity is greater.

C. The less massive object will have less momentum if the velocities are the same.

D. The more massive object will have less momentum if the velocities are the same.

Points Earned: 1/1

Your Response: C

21. If a force is exerted on an object, which statement must be true?

A. A large force always produces a large change in the object’s momentum.

B. A large force produces a large change in the object’s momentum only if the force is applied over a very short time interval.

C. A small force applied over a long time interval can produce a large change in the object’s

momentum.

D. A small force produces a large change in the object’s momentum.

Points Earned: 0/1

Your Response: B

22. A 6.0٠10–2 kg tennis ball moves at a velocity of 12 m/s. The ball is struck by a racket, causing it to rebound in the opposite direction at a speed of 18 m/s. What is the change in the ball’s momentum?

A. –0.38 kgm/s

B. –0.72 kg*m/s

C. –1.1 kg*m/s

D. –1.8 kg*m/s

Points Earned: 1/1

Your Response: D

23. The impulse experienced by a body is equivalent to the body’s change in

A. velocity.

B. kinetic energy.

C. momentum.

D. force.

Points Earned: 1/1

Your Response: C

24. When one catches a baseball, it hurts the hand if one gives with the ball. The reason this helps the hand is that

A. this makes the kinetic energy change less.

B. this makes the momentum change less.

C. this makes the time interval for stopping greater.

D. this increases the impulse of the collision.

Points Earned: 1/1

Your Response: C

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uiz 4-1Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 4/19/2012 5:45:35 PM

Points Awarded 9

Points Missed 4

Percentage 69%

1. The momentum of an object is defined as the object’s

A. mass times it acceleration. B. mass times its velocity. C. force times its acceleration. D. force times the time interval. E. velocity times the time interval.

Points Earned: 0/1

Correct Answer: B

Your Response: D


A. A baseball that is caught. B. A baseball that is thrown. C. A baseball that is caught and thrown back with the same speed. D. They all have the same impulse.

Points Earned: 1/1

Correct Answer: C

Your Response: C

3. Which of the following is true about momentum?

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A. it is a vector B. it is a product of mass times velocity C. impulses are required to change it D. all of the above E. none of the above

Points Earned: 1/1

Correct Answer: D

Your Response: D

4. A rubber ball and a lump of clay approach a wall with the same momentum. The clay sticks to the wall and the ball bounces off. Which delivers the most punch (impulse. to the wall?

A. ball B. clay C. both deliver the same amount of punch

Points Earned: 1/1

Correct Answer: A

Your Response: A

5. Why do you land with your knees bent when you jump off a tall chair?

A. To reduce your change in velocity of your body. B. To increase the interaction time on your bones. C. To increase the stopping force.

Points Earned: 0/1

Correct Answer: B

Your Response: A

6. Four masses are placed in the xy plane. Determine the coordinates of the center of mass of the system if a 2.00 kg mass is placed at (4,0), a 1.00 kg mass is placed at (3,0), a 3 kg mass is placed at (-1,-1) and a 4.00 kg mass is placed at (-1,-2).

A. (4,0) B. (4,-7) C. (0.4,-0.7) D. (-0.4,0)

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. An object with a speed of 5 m/s has 10 N-s of linear momentum. What is its mass?

A. 0.5 kg B. 2 kg

C. 5 kg D. 10 kg E. 50 kg

Points Earned: 0/1

Correct Answer: B

Your Response: D

8. A 200 g clump of clay is thrown at a wall. It collides with the wall at 15 m/s and sticks. The collision takes 0.015 s. What average force did the wall apply to the clay during the collision?

A. 0.045 N B. 3 N C. 90 N D. 200 N E. 400 N

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. A barefoot field-goal kicker imparts a velocity of 30 m/s to a football at rest. If the football has a mass of 0.5 kg and time-of-contact with the football is 0.025 s, what is the force exerted on the foot?

A. 188 N B. 375 N C. 600 N D. 900 N

Points Earned: 1/1

Correct Answer: C

Your Response: C

10. A karate-master strikes a board with an initial velocity of 10 m/s, decreasing to 1 m/s as his hand passes through the board. If the time-of-contact with the board is 0.002 s, and the mass of the coordinated hand and arm is 1 kg, what is the force exerted on the board?

A. 1000 N B. 1800 N C. 2700 N D. 4500 N

Points Earned: 1/1

Correct Answer: D

Your Response: D

11. A force of 20.0 N is applied for 2.00 s to an object with an initial momentum of 100 Ns. The change in momentum is _____ Ns.

A. 20.0 B. 22.0 C. 40.0 D. 60.0

Points Earned: 0/1

Correct Answer: C

Your Response: D

12. A pitched baseball, of mass 0.2 kg, arrives at home plate with a speed of 40 m/s and is batted straight back to the pitcher with a return speed of 60 m/s. What is the magnitude of change in the ball's momentum?

A. 4.0 kg-m/s B. 8.0 kg-m/s C. 18 kg-m/g D. 20 kg-m/g

Points Earned: 1/1

Correct Answer: D

Your Response: D

13. A child with a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s to the south. Compare the momentum of the child with the momentum of the bike.

A. Both the child and the bike have the same momentum. B. The bike has a greater momentum than the child. C. The child has a greater momentum than the bike. D. Neither the child nor the bike has momentum.

Points Earned: 1/1

Correct Answer: C

Your Response: CImportan


Points Awarded 10

Points Missed 3

Percentage 77%


A. increases the time of impact B. decreases the time of impact C. increases the force of impact D. increases kinetic energy transfer

Points Earned: 1/1

Correct Answer: A

Your Response: A


A. the golf ball undergoes the greatest change of momentum B. the putty undergoes the greatest change of momentum C. the change in momentum for each is the same D. the change depends on the angle of impact

Points Earned: 1/1

Correct Answer: A

Your Response: A


A. The object with the higher velocity will have less momentum if the masses are equal. B. The more massive object will have less momentum if its velocity is greater. C. The less massive object will have less momentum if the velocities are the same. D. The more massive object will have less momentum if the velocities are the same.

Points Earned: 1/1

Correct Answer: C

Your Response: C

4. If a force is exerted on an object, which statement is true?

A. A large force always produces a large change in the object’s momentum. B. A large force produces a large change in the object’s momentum only if the force is

applied over a very short time interval. C. A small force applied over a long time interval can produce a large change in the object’s

momentum. D. A small force produces a large change in the object’s momentum.

Points Earned: 1/1

Correct Answer: C

Your Response: C

5. A force is applied to stop a moving shopping cart. Increasing the time interval over which the force is applied

A. requires a greater force. B. has no effect on the force needed. C. requires a smaller force. D. requires the same force.

Points Earned: 1/1

Correct Answer: C

Your Response: C

6. A 3 kg object and a 4 kg object have the same kinetic energy. Which object has larger momentum?

A. the 3 kg object B. they have the same momentum C. the 4 kg D. not enough information

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. A baseball batter hits an incoming 40 m/s fastball. The ball leaves the bat at 50 m/s after a ball-on-bat contact time of 0.03 s. What is the force exerted on the 0.15 kg baseball?

A. 450 N B. 250 N C. 200 N D. 90 N

Points Earned: 1/1

Correct Answer: A

Your Response: A


A. 3.33 B. 44.0 C. 4.16 D. 720

Points Earned: 1/1

Correct Answer: A

Your Response: A

9. A force of 20.0 N is applied for 10.0 s to an object that has an initial momentum of 300 Ns. The final momentum of the object is _____ Ns.

A. 100 B. 200 C. 300 D. 500

Points Earned: 0/1

Correct Answer: D

Your Response: B

10. A force of 60.0 N is applied for 14.0 s to an object that has an initial momentum of 200 Ns. The final momentum will be _____ Ns.

A. 840 B. 1040 C. 640 D. 168,000

Points Earned: 0/1

Correct Answer: B

Your Response: C



Points Earned: 0/1

Correct Answer: D

Your Response: B


A. truck with a mass of 2250 kg moving at a velocity of 25 m/s B. car with a mass of 1210 kg moving at a velocity of 51 m/s C. truck with a mass of 6120 kg moving at a velocity of 10 m/s D. car with a mass of 1540 kg moving at a velocity of 38 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B

13. What impulse is needed to stop a 1200-kg car traveling at 20 m/s?

A. 20 N*s B. 1200 N*.s C. 60 N*s D. 24,000 N*s

Points Earned: 1/1

Correct Answer: D

Your Response: D


Points Awarded 10

Points Missed 3

Percentage 77%


A. increases the time of impact B. decreases the time of impact C. increases the force of impact D. increases kinetic energy transfer

Points Earned: 1/1

Correct Answer: A

Your Response: A


A. the golf ball undergoes the greatest change of momentum B. the putty undergoes the greatest change of momentum C. the change in momentum for each is the same D. the change depends on the angle of impact

Points Earned: 1/1

Correct Answer: A

Your Response: A



Points Earned: 1/1

Correct Answer: C

Your Response: C

4. If a force is exerted on an object, which statement is true?

A. A large force always produces a large change in the object’s momentum. B. A large force produces a large change in the object’s momentum only if the force is

applied over a very short time interval. C. A small force applied over a long time interval can produce a large change in the object’s

momentum. D. A small force produces a large change in the object’s momentum.

Points Earned: 1/1

Correct Answer: C

Your Response: C

5. A force is applied to stop a moving shopping cart. Increasing the time interval over which the force is applied

A. requires a greater force. B. has no effect on the force needed. C. requires a smaller force. D. requires the same force.

Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: C

Your Response: C

7. A baseball batter hits an incoming 40 m/s fastball. The ball leaves the bat at 50 m/s after a ball-on-bat contact time of 0.03 s. What is the force exerted on the 0.15 kg baseball?

A. 450 N B. 250 N C. 200 N D. 90 N

Points Earned: 1/1

Correct Answer: A

Your Response: A


A. 3.33 B. 44.0 C. 4.16 D. 720

Points Earned: 1/1

Correct Answer: A

Your Response: A

9. A force of 20.0 N is applied for 10.0 s to an object that has an initial momentum of 300 Ns. The final momentum of the object is _____ Ns.

A. 100 B. 200 C. 300 D. 500

Points Earned: 0/1

Correct Answer: D

Your Response: B

10. A force of 60.0 N is applied for 14.0 s to an object that has an initial momentum of 200 Ns. The final momentum will be _____ Ns.

A. 840 B. 1040 C. 640 D. 168,000

Points Earned: 0/1

Correct Answer: B

Your Response: C



Points Earned: 0/1

Correct Answer: D

Your Response: B



Points Earned: 1/1

Correct Answer: B

Your Response: B


A. 20 N*s B. 1200 N*.s C. 60 N*s D. 24,000 N*s

Points Earned: 1/1

Correct Answer: D

Your Response: D


Points Awarded 11

Points Missed 3

Percentage 79%

1. Momentum of a system is conserved only when

A. there are no forces acting on the system. B. there is no net external force acting on the system. C. there are no internal forces acting on the system. D. the system is not moving. E. the system has zero momentum.

Points Earned: 1/1

Correct Answer: B

Your Response: B

2. A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the average collision force is correct?

A. The truck experiences the greater average force. B. The small car experiences the greater average force. C. The small car and the truck experience the same average force. D. It is impossible to tell since the masses and velocities are not given.

Points Earned: 1/1

Correct Answer: C

Your Response: C

3. In a two-body collision, if the kinetic energy of the system is conserved, then which of the following best describes the momentum after the collision?

A. must be less B. must also be conserved C. may also be conserved D. is doubled in value

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. In a completely inelastic collision,

A. Momentum is not conserved. B. Kinetic energy is conserved. C. Colliding objects stick together after the collision. D. Colliding objects do not stick together after the collision.

Points Earned: 0/1

Correct Answer: C

Your Response: A

5. In which type of collision is energy conserved?

A. elastic B. inelastic C. totally inelastic D. All of the above E. None of the above

Points Earned: 1/1

Correct Answer: A

Your Response: A

6. What never changes when two or more objects collide is

A. the momentum of each one. B. the kinetic energy of each one. C. the total momentum of all the objects. D. the total kinetic energy of all the objects.

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. A large platform is initially at rest on an a smooth surface. A dog on the platform starts running toward the east. The mass of the dog is one-half the mass of the platform. When the dog moves toward the east with a speed vo, the platform moves toward the ________ with a speed ________.

A. east ... vo/2 B. east ... 2 vo C. west ... vo/2 D. west ... 2 vo E. none of these

Points Earned: 1/1

Correct Answer: C

Your Response: C

8. A 20,000 kg car moving with a speed of 4.00 m/s collides with a 50,000 kg truck car moving with a speed of 1.80 m/s in the same direction. Find the speed of the combined cars after the collision which is perfectly inelastic.

A. 1.60 m/s B. 2.43 m/s C. 2.00 m/s D. 1.57 m/s E. none of these

Points Earned: 0/1

Correct Answer: B

Your Response: C

9. A 75 kg swimmer dives horizontally off a 500 kg raft. If the diver's speed immediately after leaving the raft is 4 m/s, what is the corresponding raft speed?

A. 0.2 m/s B. 0.56 m/s C. 0.6 m/s D. 4 m/s

Points Earned: 1/1

Correct Answer: C

Your Response: C

10. A 3.0-kg object moves to the right at 4.0 m/s. It collides head-on with a 6.0-kg object moving to the left at 2.0 m/s. Which statement is correct?

A. The total momentum both before and after the collision is 24 kg˙m/s. B. The total momentum before the collison is 24 kg˙m/s, and after the collision is 0

kg˙m/s. C. The total momentum both before and after the collision is zero. D. None of the above is true.

Points Earned: 1/1

Correct Answer: C

Your Response: C

11. A bullet moving at 300 m/s is fired into a 1.00-kg block. The bullet emerges (the bullet does not embedded in the block) with half of its original speed. What is the velocity of the block right after the collision?

A. 1.50 m/s B. 97 m/s C. 3.00 m/s D. 273 m/s E. not enough information given

Points Earned: 1/1

Correct Answer: E

Your Response: E

12. An 80.0 kg man jumps with a velocity of 3.00 m/s off the bow of a 120 kg boat initially at rest. Ignoring the friction of the water on the boat, the velocity of the boat after the man jumps will be _____ m/s.

A. -2.00 B. 2.00 C. -3.00 D. -1.50

Points Earned: 0/1

Correct Answer: A

Your Response: C

13. A man is marooned at rest on level frictionless ice. In desperation, he hurls his shoe to the right at 45 ft/s. If the man weighs 180 lb and the shoe weighs 1.0 lb, the man moves to the left at approximately:

A. 1 ft/s B. 0.25 ft/s C. 32 ft/s D. 4 ft/s E. 9 ft/s

Points Earned: 1/1

Correct Answer: B

Your Response: B

14. A 1000-kg car, moving at 35 MPH, collides with another car, mass = 1500-kg, at rest. What will be the speed of the two cars just after the collision if they stick together?

A. 23 MPH B. 14 MPH C. 35 MPH D. 14 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B


Points Awarded 9

Points Missed 5

Percentage 64%

1.

A train car that is carrying half its capacity of cargo is moving north on train tracks when it collides with a stationary train car that is loaded to its capacity. The collision is elastic. After the collision,…

A. the half-loaded car is stationary and the fully loaded car moves north with the speed of the original car.

B. the half-loaded car is stationary, and the fully loaded car moves north with half the speed of the original car.

C. the half-loaded car rebounds from the collision back the way it came and the fully loaded car moves northward slowly.

D. the half-loaded car rebounds from the collision back the way it came and the fully loaded car moves northward very fast.

E. both the cars move towards the north, the half-loaded car more slowly than the fully loaded car.

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. The truck experiences the greater average force. B. The small car experiences the greater average force. C. The small car and the truck experience the same average force. D. It is impossible to tell since the masses and velocities are not given.

Points Earned: 1/1

Correct Answer: C

Your Response: C

3. Two objects collide and stick together. Linear momentum

A. is definitely conserved. B. is definitely not conserved. C. is conserved only if the collision is elastic. D. is conserved only if the environment is frictionless.

Points Earned: 1/1

Correct Answer: A

Your Response: A

4. A rubber ball and a lump of putty have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The putty sticks to the wall. Which objects experiences the greater momentum change?

A. the ball B. the putty C. Both experience the same momentum change. D. Cannot be determined from the information given.

Points Earned: 1/1

Correct Answer: A

Your Response: A

5. The law of conservation of momentum states that

A. the total initial momentum of all objects interacting with one another usually equals the total final momentum.

B. the total initial momentum of all objects interacting with one another does not equal the total final momentum.

C. the total momentum of all objects interacting with one another is zero. D. the total momentum of all objects interacting with one another remains constant

regardless of the nature of the forces between the objects.

Points Earned: 0/1

Correct Answer: D

Your Response: C

6.

An open railroad car is coasting horizontally along frictionless rails. A girl on board starts throwing coal backward straight off the car. As a result, the railroad car

A. speeds up B. slows down C. first speeds up then slows down D. travels at a constant speed

Points Earned: 1/1

Correct Answer: A

Your Response: A

7. A 1000 kg car traveling east at 20 m/s collides head on with a 1500 kg car traveling west at 10 m/s. The cars stick together after the collision. What is their common velocity after the collision?

A. 3 m/s east B. 4 m/s east C. 6 m/s west D. 14 m/s east E. none of these

Points Earned: 1/1

Correct Answer: E

Your Response: E



Points Earned: 0/1

Correct Answer: B

Your Response: C

9. A 20,000 kg car moving with a speed of 4.00 m/s collides with a 50,000 kg truck car moving with a speed of 1.80 m/s in the same direction. Find the speed of the combined cars after the collision which is perfectly inelastic. The change in kinetic energy of the truck is _____ J.

A. 160000 B. -34000 C. -101000 D. –207000 E. none of these

Points Earned: 0/1

Correct Answer: C

Your Response: A

10. A 50-kg pitching machine (excluding the baseball) is placed on a frozen pond. The machine fires a 0.40-kg baseball with a speed of 35 m/s in the horizontal friction. What is the recoil speed of the pitching machine? (Assume negligible friction.)

A. 0.14 m/s B. 0.28 m/s C. 0.70 m/s D. 4.4*103 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B




Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 0/1

Correct Answer: E

Your Response: A

13. Two astronauts, of masses 60 kg and 80 kg, are initially at rest in outer space. They push each other apart. What is their separation after the lighter astronaut has moved 12 m?

A. 15 m B. 18 m C. 21 m D. 24 m

Points Earned: 1/1

Correct Answer: C

Your Response: C

14. While skating in a straight line, a large boy collides with a small girl and has a change in momentum of 160 Ns. The change in momentum of the girl is ____ Ns.

A. -160 B. 160 C. 80.0 D. -80.0

Points Earned: 0/1

Correct Answer: A

Your Response: B


Points Awarded 11

Points Missed 3

Percentage 79%


A. there are no forces acting on the system.

B. there is no net external force acting on the system.

C. there are no internal forces acting on the system.

D. the system is not moving.

E. the system has zero momentum.

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. The truck experiences the greater average force.

B. The small car experiences the greater average force.

C. The small car and the truck experience the same average force.

D. It is impossible to tell since the masses and velocities are not given.

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. must be less

B. must also be conserved

C. may also be conserved

D. is doubled in value

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. In a completely inelastic collision,

A. Momentum is not conserved.

B. Kinetic energy is conserved.

C. Colliding objects stick together after the collision.

D. Colliding objects do not stick together after the collision.

Points Earned: 0/1

Correct Answer: C

Your Response: A

5. In which type of collision is energy conserved?

A. elastic

B. inelastic

C. totally inelastic

D. All of the above

E. None of the above

Points Earned: 1/1

Correct Answer: A

Your Response: A

6. What never changes when two or more objects collide is

A. the momentum of each one.

B. the kinetic energy of each one.

C. the total momentum of all the objects.

D. the total kinetic energy of all the objects.

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. east ... vo/2

B. east ... 2 vo

C. west ... vo/2

D. west ... 2 vo

E. none of these

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. 1.60 m/s

B. 2.43 m/s

C. 2.00 m/s

D. 1.57 m/s

E. none of these

Points Earned: 0/1

Correct Answer: B

Your Response: C

9. A 75 kg swimmer dives horizontally off a 500 kg raft. If the diver's speed immediately after leaving the raft is 4 m/s, what is the corresponding raft speed?

A. 0.2 m/s

B. 0.56 m/s

C. 0.6 m/s

D. 4 m/s

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. The total momentum both before and after the collision is 24 kg˙m/s.

B. The total momentum before the collison is 24 kg˙m/s, and after the collision is 0 kg˙m/s.

C. The total momentum both before and after the collision is zero.

D. None of the above is true.

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. 1.50 m/s

B. 97 m/s

C. 3.00 m/s

D. 273 m/s

E. not enough information given

Points Earned: 1/1

Correct Answer: E

Your Response: E

12. An 80.0 kg man jumps with a velocity of 3.00 m/s off the bow of a 120 kg boat initially at rest. Ignoring the friction of the water on the boat, the velocity of the boat after the man jumps will be _____ m/s.

A. -2.00

B. 2.00

C. -3.00

D. -1.50

Points Earned: 0/1

Correct Answer: A

Your Response: C

13. A man is marooned at rest on level frictionless ice. In desperation, he hurls his shoe to the right at 45 ft/s. If the man weighs 180 lb and the shoe weighs 1.0 lb, the man moves to the left at approximately:

A. 1 ft/s

B. 0.25 ft/s

C. 32 ft/s

D. 4 ft/s

E. 9 ft/s

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. 23 MPH

B. 14 MPH

C. 35 MPH

D. 14 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B

Important links- Report an Error -~-

our response has been submitted successfully.

Points Awarded 23

Points Missed 4

Percentage 85%


A. the object with the greater mass will have the smaller velocity B. the object with the greater mass will have the larger velocity C. both objects have the same velocity D. both objects have only the same speed

Points Earned: 1/1

Correct Answer: A

Your Response: A




Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: C

Your Response: C

4. The change in an object’s momentum is equal to

A. the product of the mass of the object and the time interval. B. the product of the force applied to the object and the time interval. C. the time interval divided by the net external force. D. the net external force divided by the time interval.

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. this makes the kinetic energy change less. B. this makes the momentum change less. C. this makes the time interval for stopping greater. D. this increases the impulse of the collision.

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. the 3 kg object B. they have the same momentum

C. the 4 kg D. not enough information

Points Earned: 1/1

Correct Answer: C

Your Response: C


A. 0.045 N B. 3 N C. 90 N D. 200 N E. 400 N

Points Earned: 1/1

Correct Answer: D

Your Response: D

8. A 0.06 kg tennis ball, initially moving at a speed of 12 m/s, is struck by a racket causing it to rebound in the opposite direction at a speed of 18 m/s. What is the change of momentum of the ball?

A. 0.36 kg m/s B. 0.72 kg m/s C. 1.08 kg m/s D. 1.80 kg m/s

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. Which has more momentum, a 50 ton earth-moving dump truck moving at 25 mph, or a 10 ton tractor-trailer moving at 75 mph?

A. 50 ton truck. B. 10 ton tractor. C. Both the same. D. Not enough information.

Points Earned: 1/1

Correct Answer: A

Your Response: A


A. truck with a mass of 2250 kg moving at a velocity of 25 m/s B. car with a mass of 1210 kg moving at a velocity of 51 m/s

C. truck with a mass of 6120 kg moving at a velocity of 10 m/s D. car with a mass of 1540 kg moving at a velocity of 38 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B



Points Earned: 1/1

Correct Answer: C

Your Response: C

12. A softball with a mass of 0.11 kg moves at a speed of 12 m/s. Then the ball is hit by a bat and rebounds in the opposite direction at a speed of 15 m/s. What is the change in momentum of the ball?

A. –1.3 kg*m/s B. –1.6 kg*m/s C. –0.33 kg*m/s D. –3.0 kg*m/s

Points Earned: 1/1

Correct Answer: D

Your Response: D


A. 20 N*s B. 1200 N*.s C. 60 N*s D. 24,000 N*s

Points Earned: 1/1

Correct Answer: D

Your Response: D


A. there are no forces acting on the system. B. there is no external forces acting on the system. C. there are no internal forces acting on the system.

D. the system is not moving. E. the system has been moving long enough to gain momentum.

F. none of these

Points Earned: 0/1

Correct Answer: B

Your Response: A

15. During an elastic collision,

A. both momentum and kinetic energy are conserved B. only momentum is conserved C. only kinetic energy is conserved D. only kinetic and potential energy are conserved

Points Earned: 1/1

Correct Answer: A

Your Response: A



Points Earned: 1/1

Correct Answer: B

Your Response: B

17. A person sitting in a chair with wheels stands, causing the chair to roll backward across the floor. The momentum of the chair

A. was zero while stationary and increased when the person stood. B. was greatest while the person sat in the chair. C. remained the same. D. was zero when the person got out of the chair and increased while the person sat.

Points Earned: 1/1

Correct Answer: A

Your Response: A

18. Two balls of dough collide and stick together. Identify the type of collision.

A. elastic B. perfectly elastic

C. inelastic D. perfectly inelastic

Points Earned: 1/1

Correct Answer: D

Your Response: D

19. A bowling ball traveling with a speed v collides with a ping-pong ball moving at a speed v, but in the opposite direction. One can conclude that the magnitude of a. the impulse imparted to the ping-pong ball is

A. less that that of the bowling ball B. greater than that of the bowling ball C. the same as that of the bowling ball

Points Earned: 0/1

Correct Answer: C

Your Response: A



Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 0/1

Correct Answer: B

Your Response: C




Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: E

Your Response: E

24. 3.0-kg object moves to the right with a speed of 4.0 m/s. It collides in a perfectly elastic collision with a 6.0-kg object moving to the left at 2.0 m/s. What is the total kinetic energy after the collision?

A. 72 J B. 36 J C. 24 J D. 0 J

Points Earned: 1/1

Correct Answer: B

Your Response: B

25. A 0.240 kg glider moving with a velocity of 0.600 m/s collides with and sticks to a 0.260 kg glider moving with a velocity of 0.200 m/s. The final velocity of the two gliders is _____ m/s.

A. 0.392 B. 0.184 C. 0.092

D. -0.092

Points Earned: 0/1

Correct Answer: A

Your Response: C

26. A 2000 kg car moving with a velocity of 6.00 m/s collides with and sticks to a 3000 kg car initially at rest. The velocity of the car after the collision will be _____ m/s.

A. 3.00 B. 6.00 C. 2.40 D. 3.60

Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: B

Your Response: BImportant links- R

our response has been submitted successfully.

Points Awarded 23

Points Missed 4

Percentage 85%


A. the object with the greater mass will have the smaller velocity B. the object with the greater mass will have the larger velocity C. both objects have the same velocity D. both objects have only the same speed

Points Earned: 1/1

Correct Answer: A

Your Response: A



Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: C

Your Response: C

4. The change in an object’s momentum is equal to

A. the product of the mass of the object and the time interval. B. the product of the force applied to the object and the time interval. C. the time interval divided by the net external force. D. the net external force divided by the time interval.

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. this makes the kinetic energy change less. B. this makes the momentum change less. C. this makes the time interval for stopping greater. D. this increases the impulse of the collision.

Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: C

Your Response: C


A. 0.045 N B. 3 N C. 90 N D. 200 N E. 400 N

Points Earned: 1/1

Correct Answer: D

Your Response: D

8. A 0.06 kg tennis ball, initially moving at a speed of 12 m/s, is struck by a racket causing it to rebound in the opposite direction at a speed of 18 m/s. What is the change of momentum of the ball?

A. 0.36 kg m/s B. 0.72 kg m/s C. 1.08 kg m/s D. 1.80 kg m/s

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. Which has more momentum, a 50 ton earth-moving dump truck moving at 25 mph, or a 10

ton tractor-trailer moving at 75 mph?

A. 50 ton truck. B. 10 ton tractor. C. Both the same. D. Not enough information.

Points Earned: 1/1

Correct Answer: A

Your Response: A



Points Earned: 1/1

Correct Answer: B

Your Response: B



Points Earned: 1/1

Correct Answer: C

Your Response: C

12. A softball with a mass of 0.11 kg moves at a speed of 12 m/s. Then the ball is hit by a bat and rebounds in the opposite direction at a speed of 15 m/s. What is the change in momentum of the ball?

A. –1.3 kg*m/s B. –1.6 kg*m/s C. –0.33 kg*m/s D. –3.0 kg*m/s

Points Earned: 1/1

Correct Answer: D

Your Response: D


A. 20 N*s B. 1200 N*.s C. 60 N*s D. 24,000 N*s

Points Earned: 1/1

Correct Answer: D

Your Response: D


A. there are no forces acting on the system. B. there is no external forces acting on the system. C. there are no internal forces acting on the system. D. the system is not moving. E. the system has been moving long enough to gain momentum.

F. none of these

Points Earned: 0/1

Correct Answer: B

Your Response: A

15. During an elastic collision,

A. both momentum and kinetic energy are conserved B. only momentum is conserved C. only kinetic energy is conserved D. only kinetic and potential energy are conserved

Points Earned: 1/1

Correct Answer: A

Your Response: A



Points Earned: 1/1

Correct Answer: B

Your Response: B

17. A person sitting in a chair with wheels stands, causing the chair to roll backward across the floor. The momentum of the chair

A. was zero while stationary and increased when the person stood. B. was greatest while the person sat in the chair. C. remained the same. D. was zero when the person got out of the chair and increased while the person sat.

Points Earned: 1/1

Correct Answer: A

Your Response: A

18. Two balls of dough collide and stick together. Identify the type of collision.

A. elastic B. perfectly elastic C. inelastic D. perfectly inelastic

Points Earned: 1/1

Correct Answer: D

Your Response: D

19. A bowling ball traveling with a speed v collides with a ping-pong ball moving at a speed v, but in the opposite direction. One can conclude that the magnitude of a. the impulse imparted to the ping-pong ball is

A. less that that of the bowling ball B. greater than that of the bowling ball C. the same as that of the bowling ball

Points Earned: 0/1

Correct Answer: C

Your Response: A



Points Earned: 1/1

Correct Answer: C

Your Response: C

21. A 20,000 kg car moving with a speed of 4.00 m/s collides with a 50,000 kg truck car

moving with a speed of 1.80 m/s in the same direction. Find the speed of the combined cars after the collision which is perfectly inelastic.


Points Earned: 0/1

Correct Answer: B

Your Response: C




Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: E

Your Response: E

24. 3.0-kg object moves to the right with a speed of 4.0 m/s. It collides in a perfectly elastic collision with a 6.0-kg object moving to the left at 2.0 m/s. What is the total kinetic energy after the collision?

A. 72 J B. 36 J C. 24 J

D. 0 J

Points Earned: 1/1

Correct Answer: B

Your Response: B

25. A 0.240 kg glider moving with a velocity of 0.600 m/s collides with and sticks to a 0.260 kg glider moving with a velocity of 0.200 m/s. The final velocity of the two gliders is _____ m/s.

A. 0.392 B. 0.184 C. 0.092 D. -0.092

Points Earned: 0/1

Correct Answer: A

Your Response: C

26. A 2000 kg car moving with a velocity of 6.00 m/s collides with and sticks to a 3000 kg car initially at rest. The velocity of the car after the collision will be _____ m/s.

A. 3.00 B. 6.00 C. 2.40 D. 3.60

Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: B

Your Response: BImportant links- R


Points Awarded 12

Points Missed 0

Percentage 100%

1. In simple harmonic motion acceleration is greatest when the:

A. x = 0

B. x = max

C. v = max

D. F = 0

E. none of these

Points Earned: 1/1

Your Response: B

2. An object makes 20 vibrations in 10 seconds. Its frequency is:

A. 2 Hz

B. 10 s

C. 0.05 Hz

D. 2 s

E. 0.50 s

Points Earned: 1/1

Your Response: A

3. A 0.25-kg object vibrates on the end of the spring with a spring constant of 200 N/m. Find the amplitude if the total energy of the system is 6.0 J.

A. 0.06 m

B. 0.17 m

C. 0.24 m

D. 4.9 m

E. 6.9 m

Points Earned: 1/1

Your Response: C

4. If a simple pendulum has a period of 2.0 s, find the pendulum's length.

A. 0.36 m

B. 0.78 m

C. 0.99 m

D. 2.45 m

Points Earned: 1/1

Your Response: C

5. If we triple the mass on a simple pendulum, frequency will be __________

A. one-third of what it was.

B. unchanged.

C. three times what it was.

D. nine times what it was.

Points Earned: 1/1

Your Response: B

6. When a body moves in a simple harmonic motion, its acceleration at the ends of its path is:

A. zero

B. less than at equilibrium

C. more than g

D. maximum

Points Earned: 1/1

Your Response: D

7. The position of a mass undergoing simple harmonic motion is given by

x(t) = 0.5 cos (pt). What is the period?

A. 0.32 sec

B. 0.5 sec

C. 1.0 sec

D. 2.0 sec

Points Earned: 1/1

Your Response: D

8. A 2-kg mass attached to the end of a spring with a spring constant of 200 N/m moves in simple harmonic motion. Find the period of the oscillations.

A. 6.30 sec

B. 0.63 sec

C. 0.1 sec

D. 10 sec

Points Earned: 1/1

Your Response: B

9. A simple pendulum on Earth has a period of 6.0 seconds. What would the period of this pendulum be on Jupiter, if the acceleration of gravity on the surface of Jupiter is 26 m/s2

A. 2.3 sec

B. 3.7 sec

C. 6.0 sec

D. 15.6 sec

Points Earned: 1/1

Your Response: B

10. A The position of a particle undergoing simple harmonic motion is given by to x = 2 cos (50 t). What is its maximum velocity?

A. 100 sin(50 t) m/s

B. 100 cos (50 t) m/s

C. 100 m/s

D. 200 m/s

E. 50 m/s

Points Earned: 1/1

Your Response: C

11. If the amplitude of the oscillation of a weight suspended from a spring is doubled, the period will:

A. remain same

B. double

C. halve

D. increase by 2

E. decrease by 2

Points Earned: 1/1

Your Response: A

12. A 0.2 kg suspended from a spring with spring constant, k = 10 N/m is undergoing simple harmonic motion. Its acceleration at the instant when it is displaced from equilibrium by -0.05 m is:

A. 1000 m/s2

B. 40 m/s2

C. 0.1 m/s2

D. 2.5 m/s2

Points Earned: 1/1

Your Response: D


Points Awarded 14

Points Missed 0

Percentage 100%

1. The density of mercury is 1.36 x 104 kg/m3. Find the mass of a 4.00*10–4 m3 sample of mercury?

A. 0.0343 kg B. 0.002 94 kg C. 2.94 kg D. 5.44 kg E. 6.29 kg

Points Earned: 1/1

Your Response: D

2. The operation of a hydraulic jack is based on _______

A. Pascal's principle. B. Bernoulli's principle. C. Archimedes' principle. D. irrotational flow. E. the continuity equation.

Points Earned: 1/1

Your Response: A

3. An object weighs 15 N in air and 13 N when submerged in water. What is the density of the object?

A. 1200 kg/m3

B. 1500kg/m3 C. 6000 kg/m3

D. 7500kg/m3

Points Earned: 1/1

Your Response: D

4. A 2 kg object displaces 10 kg of water. What is the buoyant force on the object?

A. 19.6 N B. 78.4 N C. 98 N D. 117.6 N

Points Earned: 1/1

Your Response: C

5. The pressure in fluid a function of ________________

A. depth. B. surface area. C. fluid density. D. Both A and c.

Points Earned: 1/1

Your Response: D

6. The bottom of a 60 kg boat has an area of 4.0 m2. How far below the water surface is the boat bottom? Assume that the bottom of the boat is flat.

A. 0.060 m B. 0.015 m C. 0.030 m D. 0.075 m

Points Earned: 1/1

Your Response: B

7. The pressure inside an airliner is 105 N/m2 What is the net force exerted on each square meter of the outside walls of the airliner if the outside pressure is 0.3*105 N/m2?

A. 70 N B. 700 N C. 7,000 N D. 70,000 N

Points Earned: 1/1

Your Response: D

8. The tires of a car are inflated to a gauge pressure of 2.0*105 Pa. If the area of contact of each tire with the ground is 0.024 m2, what is the weight of the car?

A. 22,100 N B. 16,000 N C. 24,300 N

D. 19,200 N

Points Earned: 1/1

Your Response: D

9. What volume of fresh water must a ship with mass of 10 million kg displace in order to float?

A. 104 m3 B. 107 m3 C. 108 m3 D. 1010 m3

Points Earned: 1/1

Your Response: A

10. A rectangular 4m x 10m swimming pool is filled to a depth of 5m. What is the force on the bottom of the pool?

A. 5*103 N B. 5*104 N C. 2*105 N D. 2*106 N

Points Earned: 1/1

Your Response: D

11. A 20,000 N truck is lifted by a 0.25-m in radius piston of a hydraulic jack. What force is applied to a 0.05-m radius piston?

A. 260 N B. 520 N C. 800 N D. 1200 N

Points Earned: 1/1

Your Response: C

12. An object floats in water with two-thirds of its volume submerged. What is the object's density?

A. 333 kg/m3 B. 1000 kg/m3

C. 790 kg/m3 D. 667 kg/m3

Points Earned: 1/1

Your Response: D

13. What fraction of a piece of wood (density is 0.8x103 kg/m3) will be beneath the surface when it floats in water?

A. 20% B. 40% C. 80% D. 100%

Points Earned: 1/1

Your Response: C

14. An object weighs 15 N in air and 13 N when fully submerged in water. What is the density of the object.

A. 330 kg/m3 B. 500 kg/m3 C. 1200 kg/m3

D. 6000 kg/m3

E. 7500 kg/m3

Points Earned: 1/1

Your Response: E

Quiz 6-1Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 4/26/2012 10:00:03 AM

Points Awarded 9

Points Missed 3

Percentage 75%

1. Find the pressure 17.4 m below the surface of a lake.

A. 1.71*105 PaB. 2.72*105 PaC. 1.18*105 PaD. 2.65*105 Pa

Points Earned: 1/1

Correct Answer: B

Your Response: B

2. An object weighs 45 N in air and 25 N when submerged in water. What is the buoyant force of the water?

A. 20 NB. 25 NC. 45 ND. 70 N

Points Earned: 1/1

Correct Answer: A

Your Response: A

3. If the density of aluminum is 2700 kg/m„, then the volume of 400 g of aluminum is _____ cm3.

A. 0.00675B. 148C. 1080D. 108

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. What is the difference in blood pressure (in SI units) between the top of the head and bottom of feet of a 1.60-m tall person standing vertically? (Density of blood = 1050 kg/m3)

A. 165B. 1.65 x 103

C. 1.65 x 104

D. 1.65 x 105

Points Earned: 1/1

Correct Answer: C

Your Response: C

5. What mass of water can be contained in a rectangular box 10 cm x 5 cm x 1 cm?

A. 0.005 kgB. 0.010 kg C. 0.025 kg D. 0.050 kg

Points Earned: 1/1

Correct Answer: D

Your Response: D

6. A geologist finds that a moon rock whose mass is 8.20 kg has an apparent mass of 6.18 kg when submerged in water. What is the density of the rock?

A. 1.25x103 kg/m3

B. 3.05x103 kg/m3

C. 4.06x103 kg/m3

D. 5.21x103 kg/m3

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. Lead has a greater density than iron, and both are denser than water. If you have two objects with the same dimensions, one made of lead and one made of iron, and the two objects are both placed in water, the buoyant force

A. will be greater for the lead object than the iron object.B. will be greater for the iron object than the lead object.C. will be the same for each object.D. is dependent on the shape of the objects

Points Earned: 0/1

Correct Answer: A

Your Response: C

8. Why does a duck float?

A. The duck weighs less than water. B. The duck can swim.C. The duck has feathersD. The duck has a smaller density than water.

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. Which has a greater buoyant force acting on it, a floating 100 lb piece of wood, or a floating 50 lb piece of wood?

A. The 100 lb piece of wood. B. The 50 lb piece of wood.C. Since both pieces of wood are floating, they experience the same buoyant force.D. There is not enough information.

Points Earned: 1/1

Correct Answer: A

Your Response: A

10. An hydraulic system has a force of 50 lbs pushing on a tube with an area of 20 cm2. At the other end of the tube, the area is 500 cm2. How much forces pushes on an object sitting on the end of the tube whose area is 500 cm2?

A. 2 lbs.B. 50 lbs.C. 1250 lbs.D. There is not enough information.

Points Earned: 0/1

Correct Answer: C

Your Response: A

11. A 20 kg block of aluminum is dropped into a full barrel of water (barrel A). A 20 kg block of lead is dropped into a different, full barrel of water (barrel B). From which barrel does more water overflow? (ρAl = 2.7 g/cc and ρPb = 11.3 g/cc.

A. aB. bC. Equal amounts of fluid will overflow from the barrels.D. There is not enough information.

Points Earned: 0/1

Correct Answer: A

Your Response: B

12. A 15 000-N car on a hydraulic lift rests on a cylinder with a piston of radius 0.20 m. If a connecting cylinder with a piston of 0.040-m radius is driven by compressed air, what force must be applied to this smaller piston in order to lift the car?

A. 600 NB. 1 500 NC. 3 000 ND. 15 000 N

Points Earned: 1/1

Correct Answer: A

Your Response: A

Self-Check 6-2Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 4/26/2012 10:17:52 AM

Points Awarded 10

Points Missed 0

Percentage 100%

1. Water flowing at 4 m/s in a horizontal pipe enters a section with radius twice as large. What is the speed of the water in the wider?

A. 1 m/s B. 2 m/s C. 8 m/s D. 16 m/s

Points Earned: 1/1

Your Response: A

2. Bernoulli's equation states that the sum of the pressure and energy per unit volume along the pipe __________

A. increases as the pipe diameter increases. B. decreases as the pipe diameter increases. C. remains constant as the pipe diameter increases. D. none of the above.

Points Earned: 1/1

Your Response: C

3. The pressure differential across an airplane wing cross section is explained by:

A. Archimedes Principle B. Bernoulli's equation C. Newton's third law D. Poiseuille's law

Points Earned: 1/1

Your Response: B

4. Water flowing at 4 m/s in a horizontal pipe of radius 6 cm enters with a radius of 3 cm. What is the speed of the water in the narrow section?

A. 1 m/s B. 2 m/s C. 8 m/s D. 16 m/s

Points Earned: 1/1

Your Response: D

5. Oil of a density of 925 kg/m3 flowing through a pipeline at a constant speed encounters a vertical bend in the pipe raising it 4.0 m. What is the difference in pressure in the oil before and after the rise?

A. +2.4 x 104 Pa B. –3.6 x 104 Pa C. +5.1 x105 Pa D. –7.2 x 105 Pa E. –1.8 x 103 Pa

Points Earned: 1/1

Your Response: B

6. The density of the liquid flowing through a horizontal pipe is 1500 kg/m3. The speed of the fluid at point A is 5.5 m/s while at point B it is 8.0 m/s. What is the difference in pressure, PB - PA, between points B and A?

A. -1.9 x 103 Pa B. +3.8 x 103 Pa C. -2.5 x 104 Pa D. +5.0 x 104 Pa E. -7.6 x 105 Pa

Points Earned: 1/1

Your Response: C

7. Water flows through a pipe of diameter 8.0 cm with a speed of 10.0 m/s. It then enters a smaller pipe of diameter 3.0 cm. What is the speed of the water as it flows through the smaller pipe?

A. 1.4 m/s B. 2.8 m/s C. 27 m/s D. 54 m/s E. 71 m/s

Points Earned: 1/1

Your Response: E

8. Water flows under pressure from one pipe into a second pipe having half the diameter. The volume flow rate in the narrow pipe is ________ that in the wide pipe and the speed of the water in the narrow pipe is _______ that in the wide pipe.

A. equal to, 4 times B. equal to, 1/4 C. 1/4, 4 times D. 1/4, 1/4

Points Earned: 1/1

Your Response: A

9. According to __________ Principle, when the velocity of a fluid is high the _______ is low.

A. Pascal's, viscosity B. Pascal's, pressure C. Bernoulli's, viscosity D. Bernoulli's, Pressure

Points Earned: 1/1

Your Response: D

10. The water level in a reservoir is constant. What is the exit velocity of water coming out through a small hall 3.0 m below the surface?

A. 2.4 m/s B. 3.0 m/s C. 5.4 m/s D. 7.7 m/s E. 49 m/s

Points Earned: 1/1

Your Response: D

Quiz 6-2Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 4/26/2012 10:59:51 AM

Points Awarded 8

Points Missed 0

Percentage 100%

1. What is the unit for ρgh in the Bernoulli’s equation?

A. kg/m3

B. N/m2 C. N/m D. N.m

Points Earned: 1/1

Correct Answer: B

Your Response: B

2. The speed of the air across the top of an airplane wing is 241 m/s when the speed of the air below the wing is 226 m/s. What is the lifting force if the area of the wing is 24.0 m2 ?

A. 1.92*105 N B. 4.52*103 N

C. 8.4*104 N D. 1.08*105 N

Points Earned: 1/1

Correct Answer: D

Your Response: D

3. The equation of continuity is based on the conservation of

A. momentumB. energyC. massD. angular momentumE. none of the above

Points Earned: 1/1

Correct Answer: C

Your Response: C

4. Where is the air pressure the greatest around the airplane wings?

A. in diagonal currentsB. aboveC. belowD. opposite the flaps

Points Earned: 1/1

Correct Answer: C

Your Response: C

5. As the speed of gas in a tube increases, the pressure

A. increasesB. can either increase or decreaseC. decreasesD. remains the same

Points Earned: 1/1

Correct Answer: C

Your Response: C

6. A pipe is 10 cm wide at its mouth, and 5 cm wide at its end. If water flows into the 10 cm end of the pipe at a speed of 5 m/s, how fast does it leave the pipe at the 5 cm end?

A. 1.25 m/sB. 2.5 m/sC. 5 m/sD. 10 m/s

E. 20 m/s

Points Earned: 1/1

Correct Answer: E

Your Response: E

7. Bernoulli’s equation states that pgh + ½ pv2 + ? is conserved (where p is the density).

A. velocityB. pressureC. viscosityD. volume times densityE. none of the above

Points Earned: 1/1

Correct Answer: B

Your Response: B

8. It takes 2.0 minutes to fill a gas tank with 40 liters of gasoline. If the pump nozzle is 1.0 cm in radius, what is the average speed of the gasoline as it leaves the nozzle? (1 000 liters = one cubic meter)

A. 0.27 m/sB. 1.1 m/sC. 11 m/sD. 64 m/s

Points Earned: 1/1

Correct Answer: B

Your Response: B


Points Awarded 9

Points Missed 1

Percentage 90%

1. A water fall is 145 m high. What is the increase in water temperature at the bottom of the falls if all of the initial potential energy goes into heating the water? (1 kcal = 4186 J).

A. 0.16 oC B. 0.34 oC C. 0.69 oC D. 1.04 oC

Points Earned: 1/1

Your Response: B

2. The natural direction of the net heat flow between two reservoirs depends on

A. their temperatures. B. their internal energy contents. C. their pressures. D. whether they are in the solid, liquid, or gaseous state.

Points Earned: 1/1

Your Response: A

3. Which of the following best describes the relationship between two systems in thermal

equilibrium?

A. No net energy is exchanged B. The volumes are equal C. The masses are equal D. Both systems have zero velocity

Points Earned: 1/1

Your Response: A

4. A piece of metal is at 10 oC (that is 50 oF, or 283 K). You heat it so that it gets twice hotter. What is the temperature of the piece of metal now?

A. 20 oC B. 100 oF C. 566 K

Points Earned: 1/1

Your Response: C

5. Convert 50 degrees Celsius to Kelvin:

A. 323.15 B. 315.15 C. 305.15 D. 275.15

Points Earned: 1/1

Your Response: A

6. Convert 473.15 degrees Kelvin to Fahrenheit

A. 360 B. 180 C. 270 D. 392 E. none of the above

Points Earned: 1/1

Your Response: D

7. The total internal energy of an object is related to the

A. object's temperature B. number of particles in the object. C. both a and b. D. neither a nor b.

Points Earned: 1/1

Your Response: C

8. Which two temperature changes are equivalent?

A. 1 K = 1 F B. 1 F = 1 C C. 1 C = 1 K D. None of the above.

Points Earned: 1/1

Your Response: C

9. When an object is broken in half,

A. the temperature and thermal energy of each half is the same as for the whole B. the temperature is one-half as much for each half, but the thermal energy for each half is

the same as for the whole C. the temperature is the same for each half as for the whole, but the thermal energy for each

half is one-half as much as for the whole D. the temperature and thermal energy for each half are half as much as for the whole

Points Earned: 1/1

Your Response: C

10. Which of the following descriptions of heat is/are correct?(1) Heat is a form of energy(2) Heat is energy transferred from one body to another due temperature difference(3) The heat absorbed by a substance always bring about an increase in temperature

A. (1) only B. (2) only C. (1) and (2) only D. (2) and (3) only E. None

Points Earned: 0/1

Your Response: D

Quiz 7-1

Submitted by 6b8d2acb-8a26-49f1-8b3e-c8d61cde3dd7 on 5/12/2012 11:20:54 AM

Points Awarded 8

Points Missed 2

Percentage 80%

1. The temperature of an object is a measure of;

A. the rate at which the object can absorb heat. B. the rate at which the object will expand C. the thermal conductivity of the object D. the thermal stress being applied to the object E. the average kinetic energy of the atoms or molecules in the substance of which the object

is formed

Points Earned: 1/1

Correct Answer: E

Your Response: E

2. What determines the direction of heat flow when two objects at different temperatures are in thermal contact?

A. which object is hotter B. which object has a higher chemical potential energy C. which object has a higher conduction coefficient

Points Earned: 0/1

Correct Answer: A

Your Response: B

3. If a 2 liter bottle of water falls off of a 3 m shelf onto the floor, how much will the temperature rise in Celsius if all heat goes into the water? About

A. 1 B. 2 C. 3 D. 5 E. 5

Points Earned: 1/1

Correct Answer: A

Your Response: A

4. From the kinetic theory of gasses, it was proved that the random kinetic energy is proportional to the____

A. Volume B. Pressure C. Temperature D. Entropy

Points Earned: 1/1

Correct Answer: C

Your Response: C

5. The total internal energy of an object is related to the

A. object's temperature B. number of particles in the object. C. both a and b. D. neither a nor b.

Points Earned: 1/1

Correct Answer: C

Your Response: C

6. A popular science fiction book is Fahrenheit 451 by Ray Bradbury. The title refers to the (Fahrenheit) temperature at which paper burns (451F). If Mr. Bradbury were writing in the Celsius scale, the name of the book would be

A. Celsius 451 B. Celsius 724 C. Celsius 233 D. Celsius 178

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. The temperature conversion equation between TF and TC is given by,

A. TC = (9/5) (TF – 32)

B. TF = (9/5) (TC

+ 32) C. TC

= 1.8 TF + 32

D. TF = (9/5) TC

+ 32

Points Earned: 1/1

Correct Answer: D

Your Response: D

8. Which of the following is a unit for energy?

A. Joule B. Calorie

C. Btu D. All of the above

Points Earned: 0/1

Correct Answer: D

Your Response: B

9. Which of the following best describes the relationship between two systems in thermal equilibrium?

A. No net energy is exchanged. B. The volumes are equal. C. The masses are equal. D. The velocity is zero.

Points Earned: 1/1

Correct Answer: A

Your Response: A

10. Which of the following increases the internal energy of a solid metal rod?

A. Raising it to a greater height. B. Throwing it through the air. C. Having the rod conduct heat. D. Having the rod absorb heat.

Points Earned: 1/1

Correct Answer: D

Your Response: D


Points Awarded 13

Points Missed 1

Percentage 93%

1. The energy that is involved in a change of phase, but does not affect temperature is called:

A. Kinetic energy B. Internal energy C. Specific heat D. Potential energy E. Latent heat

Points Earned: 1/1

Your Response: E

2. When a substance goes from a liquid state to a solid state, it

A. absorbs heat B. releases heat C. neither absorbs nor releases heat.

Points Earned: 1/1

Your Response: B

3. The natural direction of the net heat flow between two reservoirs depends on

A. their temperatures. B. their internal energy contents. C. their pressures. D. whether they are in the solid, liquid, or gaseous state.

Points Earned: 1/1

Your Response: A

4. Of the following substances, the one that requires the greatest amount of heat per kilogram for a given increase in temperature is

A. ice. B. water. C. steam. D. copper.

Points Earned: 1/1

Your Response: B

5. The heat of vaporization of a substance is

A. less than its heat of fusion.

B. equal to its heat of fusion.C. greater than its heat of fusion.D. depends on the nature of the substance.

Points Earned: 1/1

Your Response: D

6. A 0.2 kg metal object requires 502 Joules of heat to raise its temperature from 20 to 40 degrees Celsius. The specific heat capacity of the metal is,

A. 63.0 J/(kg-deg C)B. 126 J/(kg-deg C)C. 251 J/(kg-deg C)D. 502 J/(kg-deg C)

Points Earned: 1/1

Your Response: B

7. The amount of heat necessary to melt 40 grams of ice will raise the temperature of how much water from 25 C to 45 C?

A. 160 grams.B. 800 grams.C. 1080 gramsD. There is not enough information.

Points Earned: 1/1

Your Response: A

8. Compared to most metals, water has

A. a rather large specific heat.B. a rather small specific heat.C. a high melting point.D. a high boiling point.

Points Earned: 1/1

Your Response: A

9. In order for condensation to take place, one must have

A. a liquid.B. more gas than liquid.C. a regulating liquid condensate.D. something to which the gas can give up its energy.

Points Earned: 1/1

Your Response: D

10. How much heat is required to change 1 g of 0 C ice to 120 C steam?

A. 48.7 calB. 120 calC. 730 calD. 1505 cal

Points Earned: 1/1

Your Response: C

11. 150 kcal of heat raises the temperature of 2 kg of material by 400 F. What is the material's specific heat capacity?

A. l .35 kcal/kg CB. 0.75 kcal/kg CC. 0.38 kcal/kg CD. 0.19 kcal/kg C

Points Earned: 1/1

Your Response: C

12. A block of copper and a block of aluminum have the same mass and are at the same high temperature. Copper has a smaller specific heat than aluminum. Both blocks are placed on a large chunk of ice with a flat, horizontal surface on top. Assume that the area in contact with the ice is the same for each block. Which block will melt deeper into the ice?

A. The aluminum blockB. The copper blockC. Both will melt the same depth into the ice

Points Earned: 1/1

Your Response: A

13. When a material changes from a vapor to a liquid,

A. heat must be added to the materialB. no heat is transferredC. heat is emitted from the material

Points Earned: 1/1

Your Response: C

14. A puddle contains 2.5 kg of water how much energy (in J) has it absorbed if the temperature of the water rises from 15oC to 32oC during the day.

A. 6B. 80C. 1900D. 1.23 x 105

E. 1.78 x 105

Points Earned: 0/1

Your Response: C


Points Awarded 9

Points Missed 3

Percentage 75%

1. What is the specific heat of a 20 gm object if its temperature increases by 5 oC when 20 calories of heat are transferred to it?

A. 0.20 cal/gm-oCB. 0.40 cal/gm-oCC. 0.60 cal/gm-oCD. 0.85 cal/gm-oC

Points Earned: 1/1

Correct Answer: A

Your Response: A

2. How much heat in Joules is required to melt a 45 kg block of ice at zero degrees Celsius into water at zero degrees Celsius.

A. 1.7*105

B. 1.5*107

C. 5.7*106

D. 6.4*107

Points Earned: 0/1

Correct Answer: B

Your Response: C

3. The amount of heat necessary to melt one gram of a substance is known as the

A. heat of sublimation.B. heat of fusion.C. heat of regelation.D. heat of condensation.

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. The amount of heat necessary to raise the temperature one unit mass of a substance by one degree is the

A. specific heat.B. heat of vaporization.C. heat of fusion.D. heat of sublimation.

Points Earned: 1/1

Correct Answer: A

Your Response: A

5. The specific heat of water is defined as the amount of heat necessary to

A. melt one gram of ice.B. raise the temperature of one gram of water one degree Centigrade.C. increase the vapor pressure of one gram of water by one Torr.D. the difference between water's heat of vaporization and heat of fusion.

Points Earned: 1/1

Correct Answer: B

Your Response: B

6. 40 calories of heat is added to 2 grams of water at 30 C. The final temperature of the water is

A. 70 C.B. 50 C.C. 32 C.D. 10 C.

Points Earned: 0/1

Correct Answer: B

Your Response: C

7. The amount of heat necessary to melt 40 grams of ice will raise the temperature of how much water from 25 C to 45 C?

A. 160 grams.B. 800 grams.C. 1080 gramsD. There is not enough information.

Points Earned: 1/1

Correct Answer: A

Your Response: A

8. When evaporation takes place throughout the entire volume of a liquid, and not just at its surface, we say that the liquid is

A. boiling.B. critical.C. warming.D. condensing.

Points Earned: 1/1

Correct Answer: A

Your Response: A

9. How much heat is required to change 1 g of 0 C ice to 120 C steam?

A. 48.7 calB. 120 calC. 730 calD. 1505 cal

Points Earned: 1/1

Correct Answer: C

Your Response: C

10. If 2 kg of water at O 0C is to be vaporized, how much heat must be added?

A. 1080 calB. 1080 kcalC. 1280 calD. 1280 kcal

Points Earned: 0/1

Correct Answer: C

Your Response: D

11. Wood has a lower specific heat than concrete. If equal masses of wood and concrete are supplied with equal amounts of heat, the temperature rise of the wood will be ________ that of the concrete.

A. less thanB. the same asC. greater than

Points Earned: 1/1

Correct Answer: C

Your Response: C

12. It is a well-known fact that water has a higher specific heat capacity than iron. Now, consider equal masses of water and iron that are initially in thermal equilibrium. The same amount of heat, 30 calories, is added to each. Which statement is true?

A. They remain in thermal equilibrium.B. They are no longer in thermal equilibrium; the iron is warmer.C. They are no longer in thermal equilibrium; the water is warmer.D. It is impossible to say without knowing the exact mass involved and the exact

specific heat capacities.

Points Earned: 1/1

Correct Answer: B

Your Response: B


Points Awarded 16

Points Missed 1

Percentage 94%

http://jcpseschool.jefferson.kyschools.us/section/content/default.asp?WCI=pgDisplay&WCU=CRSCNT&ENTRY_ID=C6BB251583CA49CABAE2E8D76E423A6F

1. When rod 1 is heated by an amount T its length increases by L. If rod 2, which is twice as long as rod 1, is heated by the same amount, its length increase by

A. L B. 2L C. L/2

Points Earned: 1/1

Your Response: B

2. An ordinary glass is filled to the brim with 350 cm3 of water at 1000C. If the temperature decreased to 200C, how much water could be added to the glass? Neglect the volume expansion of the glass. (w = 207x10-6/0C.

A. 3.5 cm3

B. 45 cm3 C. 5.8 cm3

D. 6.7 cm3

E. 8.4 cm3

Points Earned: 1/1

Your Response: C

3. The filament of a light bulb has a temperature of 25800C and radiates 60 W of power. The emissivity of the filament is 0.36. What is the surface area of the filament?

A. 44 mm2 B. 62 mm2 C. 74 mm2 D. 91 mm2 E. 144 mm2

Points Earned: 1/1

Your Response: A

4. How long will it take to transfer 4.186 x106 J of heat through a 2.0 m2 pane of 0.3 cm thick glass ( k=0.84 J/sm0 C) if the temperature difference is 100 C.

A. 208 hr B. 20.8 hr C. 12.5 min D. 75 s E. 25 s

Points Earned: 1/1

Your Response: C

5. A sphere of radius 0.5 m, temperature 270C, and emissivity 0.85 is located in an environment of temperature 770C. What is the net flow of energy transferred to the environment in 1 sec?

A. 1045 W B. 1280 W C. 1540 W D. 2500 W E. 4000 W

Points Earned: 1/1

Your Response: A

6. As a copper wire is heated, its length increases by 0.1%. What is the change of the temperature of the wire? (alphacopper = 16.6 x 10-6/oC).

A. 120.4 oC. B. 60.2 oC. C. 30.1 oC. D. 6.0o C

Points Earned: 1/1

Your Response: B

7. What happens to a given mass of water when it is cooled from 8 oC to 4 oC?

A. It contracts. B. It expands. C. It vaporizes. D. It neither expands, vaporizes or contracts.

Points Earned: 1/1

Your Response: A

8. A hot wire radiates heat at 100 Watts. If its temperature is doubled then the power radiated will be

A. 100 W B. 200 W C. 800 W D. 1600 W E. none of these

Points Earned: 1/1

Your Response: D

9. What is the outside temperature if 16*106 of heat is lost through a 2.0 m2 pane of 0.25 cm thick glass (k=0.84 J/sm0 C) in 45 min from a house kept at 21.80C

A. 00C B. 40C C. 130C D. 24 0C

E. 280C

Points Earned: 1/1

Your Response: C

10. The coefficient of thermal expansion for iron is 12*10-6/Co. What is the change in length of a 2 meter iron rod, when its temperature changes by 100 Co?

A. 0.0024 cmB. 0.24 mC. 0.0024 mD. 0.024 m

Points Earned: 0/1

Your Response: B

11. 3.0 kg of metal A at 50 oC is placed in contact with 2.0 kg of metal B at 20 oC, and the combination is insolated (no heat exchange with the environment). If the specific heat of metal B is 3 times that of metal A, what will be the final equilibrium temperature?

A. 30.0 oCB. 35.0 oCC. 38.0 oCD. 44.5 oCE. None of the above

Points Earned: 1/1

Your Response: A

12. 50 g of copper (C = 0.093 kcal/kg C) at 75 C is put into 100 g of water. The final temperature of the mixture is 20 C. What was the initial temperature of the water?

A. 0 CB. 4CC. 15CD. 17.4 C

Points Earned: 1/1

Your Response: D

13. An aluminum wire with a thermal conductivity of 205 J/(msK) has a cross-sectional area of 2.88*10-6 m2. After 1 hour, the heat transferred down its length is 42.1 J. If the difference in temperature of the ends of the wire is 405 K, what is the length of the wire?

A. 176 mB. 2.66 mC. 20.4 mD. 5.68*10-3 m

Points Earned: 1/1

Your Response: C

14. The heat given off by 600 grams of an alloy as it cools through 800C raises the temperature of 400 grams of water from 150C to 550C. What is the specific heat of the alloy?

A. 1280 J/kg0CB. 1395 J/kg0CC. 1480 J/kg0CD. 1520 J/kg0CE. 1670 J/kg0C.

Points Earned: 1/1

Your Response: B

15. The specific heat of lead is 128 J/kg0C. 300 grams of lead shot at 1000C is mixed with 200 grams of water at 00C in an insulated container. What is the final temperature of the mixture?

A. 2.10CB. 3.20CC. 4.40CD. 5.90CE. 12.00C.

Points Earned: 1/1

Your Response: C

16. A block of ice at 0oC is added to a 150-g aluminum calorimeter cup that holds 200 g of water at 10oC. If all but 2 g of ice melt, what was the original mass of the block of ice?

A. 31.1B. 38.8C. 42.0D. 47.6

Points Earned: 1/1

Your Response: A

17. Find the mass of water at 100C that must be added to 300 kg of water at 500C to lower its temperature to 400C.

A. 50 kgB. 100kgC. 200 kgD. 300 kgE. 900 kg

Points Earned: 1/1

Your Response: B


Points Awarded 10

Points Missed 0

Percentage 100%

1. A glass pane 0.004 m thick has an area of 2 m2. On a winter day the temperature difference between the inside and the outside surfaces of the pane is 20 oC. What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.8 J/s-m-oC.)

A. 32,000 J/sB. 8,000 J/sC. 4,000 J/sD. 1,000 J/s

Points Earned: 1/1

Correct Answer: B

Your Response: B

2. At night, the temperature drops more when the sky is clear than when it is very cloudy. This difference is due to

A. convectionB. radiationC. conduction

Points Earned: 1/1

Correct Answer: B

Your Response: B

3. The fact that, in general, liquids and gases expand when heated gives rise to

A. convection currents in fluids due to changing masses.B. convection currents in fluids due to changing densities.

C. heat transfer by conduction.D. convection currents in fluids due to constant temperatures.

Points Earned: 1/1

Correct Answer: B

Your Response: B

4. The process by which a pot of water on your electric stove starts to heat is

A. conduction.B. radiation.C. convection.D. evaporation.

Points Earned: 1/1

Correct Answer: A

Your Response: A

5. Heat transfer by radiation

A. is not possible from human beings to their environment.B. does not occur from light bulbs they are too bright.C. does not require any material between the radiator and the object receiving the radiation.D. none of the above.

Points Earned: 1/1

Correct Answer: C

Your Response: C

6. A chunk of ice (T = -20C) is added to a thermally insulated container of cold water (T = 0 C). What happens in the container?

A. The ice melts until thermal equilibrium is established.B. The water cools down until thermal equilibrium is established.C. Some of the water freezes and the chunk of ice gets larger.D. None of the above.

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. The thermos bottle is used to keep a liquid cold or hot. It is constructed with a double-walled container with vacuum in between. Purpose of this construction is to minimize heat transfer by,

A. conductionB. convectionC. radiation

D. conduction & convection

Points Earned: 1/1

Correct Answer: D

Your Response: D

8. A steel wire is 200 m long at 0 oC. What is its change in length as it heats up to 35 oC. The coefficient of linear expansion is 11 x 10-6/C.

A. 6.4 x 10-8 mB. 1.8 x 10-7 mC. 7.7 x 10-2 mD. 1.8 x 10-3 m

Points Earned: 1/1

Correct Answer: C

Your Response: C

9. “A substance will expand when heated and will contract when cooled.” This statement is:

A. always trueB. always falseC. usually true, but with exceptionsD. usually false, but with exceptionsE. none of the above

Points Earned: 1/1

Correct Answer: C

Your Response: C

10. A 5.0 cm diameter steel shaft has 0.10 mm clearance all around its bushing at 20C. If the bushing temperature remains constant, at what temperature will the shaft begin to bind? Steel has a linear expansion coefficient of 11*10-6 /C.

A. 353CB. 333CC. 53CD. 680C

Points Earned: 1/1

Correct Answer: A

Your Response: A


Points Awarded 8

Points Missed 2

Percentage 80%

1. A nitrogen in the container (molar mass is 28 g/mol) has a pressure of 2.5 atm, a volume of 0.2 m3, and a temperature of 300C. What is the mass of the nitrogen?

A. 125 g B. 258 g C. 421 g D. 582 g E. 864 g

Points Earned: 1/1

Your Response: D

2. The temperature of a fixed mass of gas drops from 127 oC to 27 oC under constant pressure. Find the ratio of the new volume to the original volume.

A. 27:127 B. 127:27 C. 3:4 D. 4:3 E. 1:1

Points Earned: 1/1

Your Response: C

3.

The volume of a fixed mass of an ideal gas is doubled while the temperature is increased from 100 K to 400 K. What is the final pressure in terms of its initial pressure pi?

A. 2.00 pi

B. 3.00 pi

C. 4.00 pi

D. 0.5 pi

Points Earned: 1/1

Your Response: A

4. Ideal Gas law is given by

A. P = nRT B. PV = nRT C. PT = nRV D. PV = nkT

Points Earned: 1/1

Your Response: B

5. If 16 moles of a gas has an absolute pressure of 2 atm and a temperature of 27 oC, what is its volume? (1 atm = 1.013 105 N/m2 , R = 8.315 J/mol.K)

A. 0.055 m3

B. 0.131 m3

C. 0.018 m3

D. 0.197 m3

Points Earned: 1/1

Your Response: D

6. 10 moles of an ideal gas has a gauge pressure of 2 atm and a temperature of 200 K. If the volume of the gas is doubled and the pressure dropped to 1 atm., what is the new temperature?

A. 267 K B. 300 K C. 400 K D. 200 K

Points Earned: 1/1

Your Response: A

7. 0.08 m3 of a gas has a gauge pressure of 2 atm and a temperature of 300 K. How many molecules are there in the gas? (1 atm = 1.013 105 N/m2 , R = 8.315 J/mol.K, NA = 6.023 1023)

A. 9.75 B. 5.87 1024 C. 5.87 1023 D. 6.023 1023

Points Earned: 1/1

Your Response: B

8. If the pressure of gas is doubled and its absolute temperature is quadrupled, the volume is what factor times the original?

A. 2 B. ½ C. 1/4 D. 4

Points Earned: 0/1

Your Response: B

9. The pressure in a tank of nitrogen is 1.75*107 Pa at 20.0 °C. If the nitrogen occupies 30.0 m3 at 1 atm and 20.0 °C, find the volume of the tank.

A. 0.173 m3

B. 0.287 m3

C. 0.304 m3

D. 0.356 m3

Points Earned: 0/1

Your Response: D

10. A tire is inflated to a gauge pressure of 2.0 atm. As the car is driven, the temperature of the tire increases from 20.0 °C to 45.0 °C, and simultaneously, the volume of the tire increases by 5.0%. What is the gauge pressure of the tire at the higher temperature?

A. 1.9 atm B. 2.1 atm C. 2.3 atm D. 2.5 atm

Points Earned: 1/1

Your Response: B


Points Awarded 6

Points Missed 4

Percentage 60%

1. A tire is filled with air at 150C to a gauge pressure of 2.2*105 Pa. If the tire reaches a temperature of 380C what will the new gauge pressure be inside it?

A. 2.5*102 PaB. 3.4*103 Pa,C. 2.5*105 PaD. 6.0*107 PaE. 8.0*109 Pa

Points Earned: 0/1

Correct Answer: C

Your Response: E

2. When using the ideal gas law, PV/NT = k,

A. P can be gauge pressureB. N can be in kilogramsC. T can be in degrees CelsiusD. none of the above

Points Earned: 1/1

Correct Answer: D

Your Response: D

3.

The volume of an ideal gas at constant pressure is proportional to its

A. Fahrenheit temperature.B. Celsius temperature.C. Absolute temperature.D. Molar mass.

Points Earned: 0/1

Correct Answer: C

Your Response: B

4. If the pressure of gas is doubled, and the temperature is constant then the volume is what factor times the original?

A. 2B. ½C. 1/4D. 4

Points Earned: 1/1

Correct Answer: B

Your Response: B

5. An ideal gas occupies 400 cm3 at an absolute pressure of 250 kPa. If the volume is changed to 100 cm3 at constant temperature, what will be the new gauge pressure?

A. 1000 kPaB. 899 kPaC. 164 kPaD. 62.5 kPa

Points Earned: 1/1

Correct Answer: A

Your Response: A

6. Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen, compared to hydrogen

A. is greater.B. is less.C. is the same.D. cannot be determined since pressure and volume are not given.

Points Earned: 1/1

Correct Answer: C

Your Response: C

7. The molecular kinetic energy of a gas can be determined by knowing only

A. the number of molecules in the gas.B. the volume of the gas.C. the pressure of the gas.D. the temperature of the gas.

Points Earned: 1/1

Correct Answer: D

Your Response: D

8. A container is filled with a mixture of helium and oxygen gases. A thermometer in the container indicates that the temperature is 22¯c. Which gas molecules have the greater average speed?

A. The helium molecules do because they are monatomic.B. It is the same for both because the temperatures are the same.C. The oxygen molecules do because they are more massive.D. The helium molecules do because they are less massive.

Points Earned: 1/1

Correct Answer: D

Your Response: D

9. Calculate the rms speed of nitrogen gas at 1250c. Atomic mass of nitrogen = 14 gram.

A. 695 m/sB. 595 m/sC. 495 m/sD. 550 m/s

Points Earned: 0/1

Correct Answer: B

Your Response: C

10. Real gas will behave similar as ideal gas at(1) high temperature(2) high density(3) high pressure

A. (1) onlyB. (3) onlyC. (1) and (2) onlyD. (1) and (3) onlyE. (1), (2) and (3)

Points Earned: 0/1

Correct Answer: A

Your Response: D


Points Awarded 7

Points Missed 3

Percentage 70%

1. A fixed mass of an ideal gas having a volume of 2500 cm3 at 200 C and absolute pressure of 65 atm expands until its volume is 4000 cm3 and its absolute pressure is 45 atm. Find its new Its temperature.

A. 200

B. 42.30

C. 51.50CD. 61.80

E. 800

Points Earned: 1/1

Correct Answer: C

Your Response: C

2. What is the volume of one mole ideal gas at 300 K and at standard atmospheric pressure?

A. 23.2 lB. 24.1 lC. 24.6 lD. 25.7 l

Points Earned: 1/1

Correct Answer: C

Your Response: C

3. A process in which the pressure remains constant is called

A. adiabaticB. isochoricC. isothermalD. isobaric

E. none of the above

Points Earned: 0/1

Correct Answer: D

Your Response: A

4. How many moles is 72 grams of water.

A. 1B. 2C. 3D. 4E. none of the above

Points Earned: 1/1

Correct Answer: D

Your Response: D

5. A process that takes place at constant volume is called

A. isothermalB. isochoricC. isobaricD. adiabatic

Points Earned: 0/1

Correct Answer: B

Your Response: C

6. If the volume of an ideal gas is quadrupled, while the pressure is constant, and the original temperature was 200 K, then what was the final temperature?

A. 50B. 100C. 400D. 800

Points Earned: 1/1

Correct Answer: D

Your Response: D

7. A gas is confined to a rigid container that cannot expand as heat energy is added to it. This process is

A. isothermal.B. isochoric.C. isobaric.D. adiabatic.

Points Earned: 1/1

Correct Answer: B

Your Response: B

8. Absolute pressure is given by,

A. gauge pressure + atmospheric pressureB. gauge pressure – atmospheric pressureC. atmospheric pressure – gauge pressureD. gauge pressure + 2 atmospheric pressure

Points Earned: 1/1

Correct Answer: A

Your Response: A

9. A cylindrical container, length 30 cm and diameter 10 cm, contains 5 moles of a gas at a temperature of 250c. (R = 8.315 J/mol.K) Find the volume of the gas.

A. 0.0024 m3

B. 0.024 m3

C. 0.0042 m3

D. 0.24 m3

Points Earned: 0/1

Correct Answer: A

Your Response: C

10. An isothermal process is one in which the ________ of the system remains constant.

A. massB. pressureC. temperatureD. volume

Points Earned: 1/1

Correct Answer: C

Your Response: C


Points Awarded 11

Points Missed 1

Percentage 92%

1. What is the efficiency of a Carnot engine operating between 100 oC and 0 oC?

A. 7% B. 15% C. 27% D. 51%

Points Earned: 1/1

Your Response: C

2. Find the change in internal energy of a system which receives 70 J of heat from its environment and does 20 J of work.

A. 90 J B. 50 J C. Zero D. -70 J

Points Earned: 1/1

Your Response: B

3. A 1 kg chunk of ice at 273 K and 1 atmosphere melts completely in water at 273 K. What is its change in entropy? (Lf = 3.34*105 J/kg)

A. 3340.0 J/K B. 2168.7 J/K C. 613.6 J/K D. 1223.4 J/K

Points Earned: 1/1

Your Response: D

4. Heat is applied to an ice-water mixture to melt the ice. In this process

A. work is done by the ice-water mixture. B. the temperature increases.

http://jcpseschool.jefferson.kyschools.us/section/content/default.asp?WCI=pgDisplay&WCU=CRSCNT&ENTRY_ID=CE538542E6384D248F5F86DFC3D5B54B

C. the internal energy increases. D. all of the above.

Points Earned: 0/1

Your Response: D

5. An ideal gas is maintained at a constant pressure of 70,000 Pa during an isobaric process and its volume decreases by 0.2 m3. What work is done by the system on its environment?

A. 14,000 J B. 350,000 J C. -14,000 J D. -35,000 J

Points Earned: 1/1

Your Response: C

6. The exhaust temperature of a Carnot heat engine is 573 K. What is the intake temperature if the efficiency of the engine is 30%?

A. 756 K B. 819 K C. 711 K D. 923 K

Points Earned: 1/1

Your Response: B

7. The internal energy of an ideal gas depends on

A. its volume. B. its pressure. C. its temperature. D. all of the above.

Points Earned: 1/1

Your Response: C

8. A gas is quickly compressed in an isolated cylinder. This process is

A. isothermal. B. isometric. C. isobaric. D. adiabatic.

Points Earned: 1/1

Your Response: D

9. What is the change of entropy associated with 3.0 kg of water freezing to ice at 0.oC? (Lf = 3.34*105 J/kg)

A. +3.7 kJ/K B. -3.7 kJ/K C. 1.0 kcal/K D. -1.1 kcal/K

Points Earned: 1/1

Your Response: B

10. An ideal gas with internal energy U at 200øC is heated to 400 oC. Its internal energy will be

A. U. B. 2 U. C. 1.4 U. D. 1.2 U.

Points Earned: 1/1

Your Response: C

11. A heat engine operates in a Carnot cycle between 80.0 oC and 350 oC. It receives 21000 J of energy per cycle from the hot reservoir. The duration of each cycle is 1.00 s. What is the mechanical power of this engine?

A. 21 kW B. 910 kW C. 9.10 kW D. 120 kW

Points Earned: 1/1

Your Response: C

12. What is the internal energy of 7.91*1022 gas molecules at a temperature of 300 K?

A. 164 J B. 109 J C. 44.2 J D. 3740 J

Points Earned: 1/1

Your Response: A


Points Awarded 10

Points Missed 2

Percentage 83%

1. A block of ice of a mass of 1 kg at 273 K melts, taking in 80,000 cal of heat from air. Which of the following best describes what happens to the ice-air system?

A. Entropy increasedB. Entropy decreasedC. Entropy has not changedD. Work converted to energy

Points Earned: 1/1

Correct Answer: A

Your Response: A

2. A Carnot engine is operated as a refrigerator, taking in 18.J of heat every second and expelling 20.J into a 23.oC room. What is the temperature inside the refrigerator?

A. 3.oCB. 15.oCC. -15.oCD. -3.oC

Points Earned: 0/1

Correct Answer: D

Your Response: B

3. What is the maximum efficiency of a heat engine that operates between 200 Celsius and 500 Celsius?

A. 61B. 40C. 32D. 39E. none of the above

Points Earned: 1/1

Correct Answer: D

Your Response: D

4. Entropy is a measure of

A. orderB. disorderC. energy

D. timeE. none of the above

Points Earned: 1/1

Correct Answer: B

Your Response: B

5. Entropy usually

A. increasesB. stays the sameC. decreasesD. all of the above.

Points Earned: 0/1

Correct Answer: A

Your Response: D

6. Assume that somehow (the third law of thermodynamics notwithstanding) a solid has reached absolute zero. We would then say that the solid’s molecules’

A. total kinetic energy is zero.B. average kinetic energy is zero.C. total potential energy is zero.D. (a) and (b) but not (c).E. (a) and (c) but not (b).

Points Earned: 1/1

Correct Answer: D

Your Response: D

7. An ideal gas is compressed isothermally from 30 L to 20 L. During this process, 6.0 J of energy is expended by the external mechanism that compressed the gas. What is the change of internal energy for this gas?

A. 6.0 JB. zeroC. -6.0 JD. none of the above

Points Earned: 1/1

Correct Answer: B

Your Response: B

8. A heat engine has an efficiency of 35.0% and receives 150 J of heat per cycle. How much work does it perform in each cycle?

A. zeroB. 52.5 J

C. 97.5 JD. 150 J

Points Earned: 1/1

Correct Answer: B

Your Response: B

9. The efficiency of a Carnot engine is 35.0%. What is the temperature of the cold reservoir if the temperature of the hot reservoir is 500 K?

A. 175 K B. 325 KC. 269 KD. 231 K

Points Earned: 1/1

Correct Answer: B

Your Response: B

10. Three reversible engines, A, B, and C, use the same cold reservoir for their exhaust heats. However, they use different hot reservoirs that have the following temperatures: (A) 950 K, (B) 720 K, and (C) 1130 K. Rank these engines in order of decreasing efficiency (largest efficiency first).

A. A, B, CB. A, C, BC. B, A, CD. B, C, AE. C, A, BF. C, B, A

Points Earned: 1/1

Correct Answer: E

Your Response: E

11. What is the maximum theoretical efficiency possible for an engine operating between 100øC and 400øC?

A. 40%B. 46%C. 30%D. 26%

Points Earned: 1/1

Correct Answer: B

Your Response: B

12. The ignition stage in a cylinder in a standard internal combustion engine is

considered an

A. ambient temperature change.B. adiabatic process.C. isovolmic process.D. isobaric process.

Points Earned: 1/1

Correct Answer: C

Your Response: C

Test 8Your response has been submitted successfully.

Points Awarded 15

Points Missed 7

Percentage 68%

1. A fixed mass of oxygen (O2, mol . mass = 32 g/mol) is contained in a cylinder whose volume is 0.0028 m3. The pressure of 148 atm when the temperature is 230c. Find the mass of oxygen in the cylinder.

A. 20 gB. 80 gC. 140 gD. 280 gE. 552 g

Points Earned: 0/1

Correct Answer: E

Your Response: D



Points Earned: 1/1

Correct Answer: D

Your Response: D

3. For ideal gases, the ratio PV/T is

A. equal to Avogadro's number.B. equal to Boltzmann constant.C. independent of the number of molecules.D. independent of the chemical nature of the molecules.

Points Earned: 1/1

Correct Answer: D

Your Response: D

4. The absolute temperature of an ideal gas is directly proportional to

A. the average number of molecules in the gasB. the average kinetic energy of the gasC. the average diffusion constant of the gas

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. 50B. 100C. 400D. 800

Points Earned: 1/1

Correct Answer: D

Your Response: D



Points Earned: 1/1

Correct Answer: B

Your Response: B



Points Earned: 1/1

Correct Answer: D

Your Response: D



Points Earned: 1/1

Correct Answer: D

Your Response: D



Points Earned: 1/1

Correct Answer: C

Your Response: C

10. A container contains a fixed mass of gas. Increase the temperature of the gas can lead to an increase of pressure. By using kinetic theory, this can be explained by

A. The collisions between gas molecules becomes more frequent.

B. The gas molecules expand.C. The collisions between gas molecules and the inner wall of container becomes

more frequent.D. The volume of the gas decreases.E. The temperature of the gas is inversely proportional to its pressure.

Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: A

Your Response: A

12. The air in this room consists of countless tiny, independent molecules. You can be sure that these air molecules will not all shift spontaneously to the other side of the room (leaving you in a vacuum) because that would

A. violate Newton’s laws of motion.B. be extremely unlikely and therefore violate the 2nd law of thermodynamicsC. violate Boltzmann’s equationD. not conserve energy and therefore violate the 1st law of thermodynamics.

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. orderB. disorderC. energyD. timeE. none of the above

Points Earned: 1/1

Correct Answer: B

Your Response: B

14. A student takes a 5 kg block of ice at 0K and place it on a large rock outcropping and

watches the ice melt. What is the entropy change (ignore sign) of the ice (water)? (choose the closest answer)

A. 423B. 5101C. 6117D. 7116E. 12,449

Points Earned: 1/1

Correct Answer: C

Your Response: C

15. Find the efficiency of the heat engine that exhausts 2000 J of heat in the process of doing 800 J of work.

A. 66.7%B. 60.0%C. 40.0%D. 28.6%E. None of the above answers

Points Earned: 0/1

Correct Answer: D

Your Response: A

16. 200 J of work is done in compressing a gas adiabatically. What is the change in internal energy of the gas?

A. ZeroB. 100 JC. +200 JD. There is not enough information to determine.

Points Earned: 0/1

Correct Answer: C

Your Response: A

17. Ten joules of heat energy are transferred to a sample of ideal gas at constant volume. As a result, the internal energy of the gas

A. increases by 10 J.B. increases by less than 10 J.C. increases by more than 10 J.D. remains unchanged.

Points Earned: 0/1

Correct Answer: A

Your Response: B

18. If the theoretical efficiency of a Carnot engine is to be 100%, the heat sink must be

A. at absolute zero.B. at 0¯c.C. at 100¯c.D. infinitely hot.

Points Earned: 1/1

Correct Answer: A

Your Response: A

19. When 5.2 x 105 J of heat are added to a gas enclosed in a cylinder fitted with a light frictionless piston maintained at atmospheric pressure, the volume is observed to increase from 1.8 m3 to 4.2 m3. The change in internal energy of the gas is:

A. 5.2 x 105 JB. 7.63 x 105 JC. 2.43 x 105 JD. 2.77 x 105 J

Points Earned: 0/1

Correct Answer: D

Your Response: A

20. Which of the following processes is impossible?

A. A quantity of heat is completely converted into mechanical energy.B. A quantity of mechanical energy is completely converted into heatC. Heat is conveyed continuously from a cold object to a hot object with the addition

of external work.D. Heat is conveyed continuously from a hot object to a cold object with the addition

of external work.

Points Earned: 0/1

Correct Answer: A

Your Response: C

21. Which of the following is (are. necessary for a gas to undergo an adiabatic process?

A. The gas cannot change its volume.B. The container that the gas is in is well insulated.C. The process occurs "quickly".D. (b) or (c) but not (a).E. (a) or (b) or (c).

Points Earned: 1/1

Correct Answer: D

Your Response: D

22. Entropy is a measure of ________. In other words, as the order of a system increases, the entropy ________.

A. order … increasesB. order … decreasesC. disorder … increasesD. disorder … decreases

Points Earned: 0/1

Correct Answer: D

Your Response: C

Test 8Your response has been submitted successfully.

Points Awarded 15

Points Missed 7

Percentage 68%

1. A fixed mass of oxygen (O2, mol . mass = 32 g/mol) is contained in a cylinder whose volume is 0.0028 m3. The pressure of 148 atm when the temperature is 230c. Find the mass of oxygen in the cylinder.

A. 20 gB. 80 gC. 140 gD. 280 gE. 552 g

Points Earned: 0/1

Correct Answer: E

Your Response: D



Points Earned: 1/1

Correct Answer: D

Your Response: D

3. For ideal gases, the ratio PV/T is

A. equal to Avogadro's number.B. equal to Boltzmann constant.C. independent of the number of molecules.D. independent of the chemical nature of the molecules.

Points Earned: 1/1

Correct Answer: D

Your Response: D

4. The absolute temperature of an ideal gas is directly proportional to

A. the average number of molecules in the gasB. the average kinetic energy of the gasC. the average diffusion constant of the gas

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. 50B. 100C. 400D. 800

Points Earned: 1/1

Correct Answer: D

Your Response: D



Points Earned: 1/1

Correct Answer: B

Your Response: B



Points Earned: 1/1

Correct Answer: D

Your Response: D



Points Earned: 1/1

Correct Answer: D

Your Response: D



Points Earned: 1/1

Correct Answer: C

Your Response: C

10. A container contains a fixed mass of gas. Increase the temperature of the gas can lead to an increase of pressure. By using kinetic theory, this can be explained by

A. The collisions between gas molecules becomes more frequent.B. The gas molecules expand.C. The collisions between gas molecules and the inner wall of container becomes

more frequent.D. The volume of the gas decreases.E. The temperature of the gas is inversely proportional to its pressure.

Points Earned: 1/1

Correct Answer: C

Your Response: C



Points Earned: 1/1

Correct Answer: A

Your Response: A

12. The air in this room consists of countless tiny, independent molecules. You can be sure that these air molecules will not all shift spontaneously to the other side of the room (leaving you in a vacuum) because that would

A. violate Newton’s laws of motion.B. be extremely unlikely and therefore violate the 2nd law of thermodynamicsC. violate Boltzmann’s equationD. not conserve energy and therefore violate the 1st law of thermodynamics.

Points Earned: 1/1

Correct Answer: B

Your Response: B


A. orderB. disorderC. energyD. timeE. none of the above

Points Earned: 1/1

Correct Answer: B

Your Response: B

14. A student takes a 5 kg block of ice at 0K and place it on a large rock outcropping and watches the ice melt. What is the entropy change (ignore sign) of the ice (water)? (choose the closest answer)

A. 423B. 5101C. 6117D. 7116E. 12,449

Points Earned: 1/1

Correct Answer: C

Your Response: C

15. Find the efficiency of the heat engine that exhausts 2000 J of heat in the process of doing 800 J of work.

A. 66.7%B. 60.0%C. 40.0%D. 28.6%E. None of the above answers

Points Earned: 0/1

Correct Answer: D

Your Response: A

16. 200 J of work is done in compressing a gas adiabatically. What is the change in internal energy of the gas?

A. ZeroB. 100 JC. +200 JD. There is not enough information to determine.

Points Earned: 0/1

Correct Answer: C

Your Response: A

17. Ten joules of heat energy are transferred to a sample of ideal gas at constant volume. As a result, the internal energy of the gas

A. increases by 10 J.B. increases by less than 10 J.C. increases by more than 10 J.D. remains unchanged.

Points Earned: 0/1

Correct Answer: A

Your Response: B

18. If the theoretical efficiency of a Carnot engine is to be 100%, the heat sink must be

A. at absolute zero.B. at 0¯c.C. at 100¯c.D. infinitely hot.

Points Earned: 1/1

Correct Answer: A

Your Response: A

19. When 5.2 x 105 J of heat are added to a gas enclosed in a cylinder fitted with a light frictionless piston maintained at atmospheric pressure, the volume is observed to increase from 1.8 m3 to 4.2 m3. The change in internal energy of the gas is:

A. 5.2 x 105 JB. 7.63 x 105 JC. 2.43 x 105 JD. 2.77 x 105 J

Points Earned: 0/1

Correct Answer: D

Your Response: A

20. Which of the following processes is impossible?

A. A quantity of heat is completely converted into mechanical energy.B. A quantity of mechanical energy is completely converted into heatC. Heat is conveyed continuously from a cold object to a hot object with the addition

of external work.D. Heat is conveyed continuously from a hot object to a cold object with the addition

of external work.

Points Earned: 0/1

Correct Answer: A

Your Response: C

21. Which of the following is (are. necessary for a gas to undergo an adiabatic process?

A. The gas cannot change its volume.B. The container that the gas is in is well insulated.C. The process occurs "quickly".D. (b) or (c) but not (a).E. (a) or (b) or (c).

Points Earned: 1/1

Correct Answer: D

Your Response: D

22. Entropy is a measure of ________. In other words, as the order of a system increases, the entropy ________.

A. order … increasesB. order … decreasesC. disorder … increasesD. disorder … decreases

Points Earned: 0/1

Correct Answer: D

Your Response: C

8-Self2

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