& / or

HW Due today

Read and STUDY 2.0 – 2.4.Finish up to #19 in the POGIL

HW assigned today

Sell a Car project due Oct 28. On p. 26-27, complete #28-30; 43-44.TEST on Ch. 2 on Nov.1 – study guides will be given out on Thurs. BRING THE CONCEPT DEVELOPMENT ½ sheets back with you on Thurs!

Do Now… Take a clicker…then, 5 minutes to complete #20-28 Check Questions

on the BACK of your POGIL – can work with others - GO!

Speed changes by…

Speeding Up

Slowing Down& / or

& / or& / or

If an object is CHANGING VELOCITY BY……

Speeding UpThen it is Positively

Accelerating

Slowing DownThen it is Negatively

Accelerating

Changing direction Then it is ACCELERATING (Centripetal acceleration… we will learn about

this in Ch. 9)

20. True or False: Acceleration ONLY occurs if the speed INCREASES

1 2 3 4

4%0%0%

96%1. True2. False3. Not enough info

to say4. Not sure

21. If velocity in a vehicle is CONSTANT, is the vehicle accelerating?

1 2 3 4

4%8%

4%

84%1. Yes2. No 3. Not enough info

to say4. Not sure

22. Suppose you are driving a car at a constant velocity of 50 mi/h. What is your acceleration?

1 2 3 4 5

92%

4% 4%0%0%

1. 02. Less than 50, but not 03. More than 504. Not enough info to say5. Not sure

23. Suppose a car moving in a straight line steadily increases its speed each second, first from 35 to 40 km/h, then from 40 to 45 km/h, then from 45 to 50 km/h, What is its acceleration?

1 2 3 4 5

0%

100%

0%0%0%

1. 02. 5 km/h s3. Less than 5 km/h s4. More than5 km/h s5. Not sure

24. In 5 seconds a car moving in a straight line increases its speed from 50 km/h to 65 km/h. During those same 5 seconds, a truck goes from rest to 15 km/h. Which has the larger acceleration?

1 2 3 4

16%

0%

60%

24%

1. Car2. Truck3. Same 4. Not sure

25. Is it possible to be moving but not accelerating?

1 2 3 4

92%

0%0%8%

1. Yes2. No 3. Not enough info

to say4. Not sure

26. Why is it that an object can accelerate while traveling at constant speed, but not at constant velocity?

Because it can travel at a constant speed and CHANGE DIRECTION (accelerating!)But…constant velocity means it’s not changing velocity, and therefore not accelerating

27. Light travels in a straight line at a constant speed of 300,000 km/s. What is the light´s acceleration?

1 2 3 4 5

100%

0% 0%0%0%

1. 02. Less than 300,000 but

not 03. More than 300,0004. Not enough info to say5. Not sure

28. Which has more acceleration when moving in a straight line- a car increasing its speed from 50 to 60 km/hr, or a bicycle that goes from zero to 10 km/hr in the same time?

1 2 3 4 5

0% 0% 0%0%

100%1. Car 2. Bike3. Same 4. Not enough info to say5. Not sure

Now, take out your HW from last night…POGIL

• 4 minutes to check, correct, ask questions, and get the help you need.

16. a = -10 m/s2 or -10m/s.s in a straight line (**Slowing down negative acceleration!**)

17. a = 2 mi/h.s east (Speeding up + acceleration!)

18. Final velocity = 100 m/s in a straight line19. Initial velocity = 20 m/s in a straight line**CAREFUL! Your units MUST MATCH on both sides of

the equation! USE DA!**

Is the final velocity even reasonable? NO WAY! The final velocity is 140 m/s which is about 313 miles per hour!

Now, take out your HW from 2 nights ago… p. 25, #9-14

9. What quantity describes how quickly you change how fast you’re traveling, or how quickly you change direction?

1 2 3 4 5 6

0%

17%

0%0%0%

83%

1. Speed2. Velocity 3. Acceleration4. Distance5. Displacement6. Not sure

10. Acceleration is the rate at which what CHANGES??

1 2 3 4 5 6

0%

96%

4%0%0%0%

1. Speed2. Velocity 3. Acceleration4. Distance5. Displacement6. Not sure

11. What is the acceleration of a car that travels in a straight line at a constant speed of 100 km/h in 10 s?

1 2 3 4 5 6

64%

32%

0%0%0%4%

1. 0 2. 10 km/hs in a straight line 3. 100 km/hs in a straight

line 4. 1000 km/hs in a straight

line 5. Answer is not listed 6. Not sure

12. What is the acceleration of a car moving along a straight-line path that increases its speed from zero to 100 km/h in 10s?

1 2 3 4 5 6

4%

96%

0%0%0%0%

1. 02. 10 km/hs in a straight line 3. 100 km/hs in a straight line 4. 1000 km/hs in a straight line 5. Answer is not listed 6. Not sure

13. By how much does the speed of a vehicle moving in a straight line change each second when it is accelerating at…

2 km/ h/s? At 4 km/h/s? At 10 km/h/s?

2 km/h4 km/h

10 km/h

14. Why does the unit of time enter twice in the unit of acceleration?

Because acceleration is a rate of a rate.Or, once for velocity and again for accleration Etc.

LABS Returned • In lab groups, you are to review the comments on the

graded copy together

• You must ALL make corrections on your OWN PAPERS for complete –(the notes become your study tool for the

TEST, and an aid during QUIZZES)• Project Managers can ask me questions about the

grading if needed. • You are also getting quizzes back –

please MAKE CORRECTIONS for the same reasons as above!

1 m/s to the right, because…• constant velocity•Or not speeding up, slowing down, or changing direction•Or we are told to neglect friction, so no increase or decrease in velocity ETC..

1 m/s

5 s

d = [v1 Δt] + [½ a(Δt)2]Using what you already know about these symbols, what do you think this equation means IN WORDS?

Distance = the quantity: initial velocity multiplied by time. This is added to the quantity: one half the acceleration multiplied by the square of the time

d = [v1 Δt] + [½ a(Δt)2]Using what you already know about these symbols, what do you think this equation means IN WORDS?

If something starts from REST…how can this equation be simplified? d = ½ a(Δt)2

Distance = the quantity: one half the acceleration multiplied by the square of the time

Do you notice a pattern with the velocities?

Increasing by 2m/s EACH SECOND

ID Name Class DateMetric HW Quiz #1

Grade I EXPECTED to earn

Grade I ACTUALLY earned

WHY?

Give DETAIL here. Was there something YOU could have done differently? Was there something I could have done differently? Were you not prepared? If so, why not? Do you understand NOW? Etc…

LAB

Grade I EXPECTED to earn

Grade I EXPECTED to earn

WHY?

Give DETAIL etc…