Beath High School - Int 1 Physics1 Intermediate 1 Physics Movement Questions and Answers.

Beath High School - Int 1 Physics 1

Intermediate 1 Physics

MovementQuestions

andAnswers


Intermediate 1 Physics Movement

Questions 1 to 13(Forces)

Questions 14 to 26(speed & acceleration)

Questions 27 to 35(Moving bodies)


1. Describe how to use a newton balance.

Use a diagram in your answer.

Hold the balance steady, for example by attaching it to a fixed support.Hang the object to be weighed on the balance.

Take a reading of the weight from where the pointer is on the scale.


2. Calculate the weights of the following objects:

(a) a 1 kg bag of sugar

(b) a person of mass 75 kg

(c) a 0.1 kg apple

(d) a 420 g can of beans

Weight = mass x g= 1 x 10= 10 newtons

Weight = m x g = 75 x 10= 750 newtons

Weight = mg = 0.1 x 10= 1 N

Weight = mg= 0.42 x 10= 4.2 N

(e) a 35 g packet of crispsW = mg = 0.035 x 10= 0.35 N


3. Susan feels she gets far too much homework. She decides to pile all her homework for a month into a barrow and weigh it. However, she finds that she has to stand on the weighing machine herself or else the barrow will tip over. The combined weight of Susan, the barrow and the month's homework is 670 newtons. Susan knows her own mass, is 55 kg and the mass of the barrow is marked on it as 8 kg.Calculate the mass of homework Susan does in a

month.Mass of (Susan + barrow + homework) = weight/10 = 670/10 = 67 kgMass of homework = total mass – (55 + 8)

= 67 – (63) = 4 kg


4. An astronaut has a mass of 70 kg.When far out in space the astronaut hasno weight, but is still 70 kg.Explain why it is possible for the astronautto have no weight, but still have mass.

Weight is the force of attraction a planet exerts.

Far out in space there is no planet to attract theastronaut; so he/she has no weight.

Mass (which is measured in kilograms) is a measure of

the amount of substance in an object and so cannot

change wherever it is.


5. The diagram below shows two identical boxes, A and B, suspended by identical springs.One box contains 50 pound coins, theother contains 50 pennies.

Which box contains the £50? Explain your choice.

The spring holding box B has stretched more than A.

This means that box B must be heavier than A.Therefore, box B contains the 50 pound coins,

because pound coins weigh more than pennies.

A

B


6. Complete the following sentences:

Friction is a force caused by the of twosurfaces.

rubbing

Friction opposes the of an object.motion

Friction can also keep objects from starting to .

move


7. Friction is not always a bad thing.

In many situations we want to use the force of friction.

The force of friction between your hand and the

lid gives you a good grip.

What role does the force of friction play in thefollowing cases?

(a) Opening a tight bottle top or jam jar lid

It helps wear the wood down to a smooth surface.

(b) Sanding wood




The force of friction between the shoes and thefloor gives a good grip.


(c) Sports shoes on gym floors

It helps give a good grip and prevent slipping.

(d) Walking on icy pavements




The force of friction changes the kinetic energyto heat.


(e) Warming hands by rubbing

The friction with the rough surface producesenough heat to light the match.

(f) Striking a match

It helps the tyres get a good grip on the road.(g) Car tyres for wet conditions


8. Often we want to reduce the force of friction.

How is it reduced in the following cases?

Oil is used as a lubricant, allowing the surfaces to

slip over each other.

(a) Metal engine parts moving against each other

The hovercraft ‘floats’ along on a cushion of airwhich separates it from the ground.

(b) A hovercraft

The ice is a smooth, slippery surface.

(c) Skates on ice


8. Often we want to reduce the force of friction.

How is it reduced in the following cases?

Oil is used as a lubricant, allowing the surfaces to

slip over each other.

(d) Door hinges

The cyclist bends forward to reduce airresistance.

(e) Air resistance of a racing cyclist


9. What force is streamlining designed to reduce?

Air resistance


10. Car manufacturers try to improve the streamlining of their cars.

It helps them cut through the air more easily.This allows them to go faster and use less fuel.

(a) Why is it useful for cars to be streamlined?

(b) What are the two main things done to a car to improve streamlining?

They are smoothly shaped like a teardrop.They are often fitted with spoilers at the back.They run close to the road.


11. The picture shows an astronaut with a jet pack.

The astronaut is on Earth during training for

a space mission and is hovering in mid air.(a) The diagram shows two forces as arrows.

Name these forces.Down force = weightUp force = thrust of jet engine

(b) How do the values of these forces comparewith each other?

They are equal in size (and opposite in direction),

since the astronaut is not accelerating.


11. The picture shows an astronaut with a jet pack.

Later, when far away in space, the astronaut

fires his jet pack in the same way as on Earth

training but finds that he moves away from

the space craft.

(c) Explain why he does not hover on this occasion.

There is no weight in deep space to balance the thrust of the jet engine.

The astronaut has an unbalanced force acting and so accelerates.


12. In tug-of-war games both teams are often pulling.

Explain why neither team moves.

The forces are balanced because they are equal and

opposite.


13. A skydiver is falling at a very high constant speed - before she opens her parachute.

(a) What force pulls her towards the ground?

Her weight.i.e. the attractive force due to gravity.(but not just ‘gravity’)

(b) What is the name of the force that is balancing this?air resistance

(c) How does the sky diver use friction to reduce this high speed before reaching the ground?opening the parachute causes the air

resistanceupwards to be much bigger than her weight

down.


14. What two measurements must be taken before you can calculate the average speed of a moving object?

the total distance travelled

the total time taken to travel that distance


15. You are asked to find the average speed of a car driving along a main road.You are given a measuring tape and a stopwatch

(a) Describe clearly your procedure and what measurements you would take.

Use the tape to measure out a reasonably largedistance (e.g. 100m).Use the stopwatch to measure the time the cartakes to cover that distance.

(b) A driver notices you with your stopwatch and brakes slightly. What effect will this have on the average speed?

the average speed will be reduced


16. A car travels 52 metres in 4 seconds.Calculate the average speed on the car in metres per second.

52

Average speed =distance

time

=4

= 13 m/s


17. A trolley moves a distance of 10 metres in 2.5 seconds.What is the average speed of the trolley?

10


time

=2.5

= 4.0 m/s


18. A girl on a train measures the time for the train to pass two stations as 2 minutes and 30 seconds. From a map, she finds that the stations are 6 kilometres apart.Calculate the average speed of the train between the two stations.

6000


time

=150

= 40 m/s


19. A student takes five minutes to walk from the playground to his class which is 200 m away.What is his average speed?.

200


time

=300

= 0.67 m/s


20. Do police radar guns measure average or instantaneous speeds? Why?

They measure instantaneous speed.

This is because the time taken for the measurement

is very short.


21. How can you tell that the speedometer in a car is measuring the instantaneous speed of the car?

The reading changes all the time as the car speeds

up and slows down.


22. How can you measure the instantaneous speed of a toy car at the bottom of a track?

You need a light gate, an electronic timer and a card

on the toy car.

(a) Describe what equipment you need, what measurements are needed and how you calculate the instantaneous speed.

Allow the toy car to run down the track and breakthe beam with the card.Measure the time taken to break the light beam.

Measure the length of the card on the car.

Divide the length of the card by the time on thetimer.


22. How can you measure the instantaneous speed of a toy car at the bottom of a track?

Very short times and distances are used to measure

the instantaneous speed.

(b) Describe the main differences in measuring the instantaneous speed and average speed of the car.


23. David measures the time taken for a mask on a trolley to pass through a light gate as 0.6 seconds.The length of the trolley is 15 centimetres.(a) What is the speed?

He has found the instantaneous speed(because it has been found over a very short

time).

speed =length of card

time on timer=

0.15

0.6= 0.25 m/s

(b) State whether David has measured the average speed or the instantaneous speed of the trolley.


24. Describe what is meant by the term acceleration.

acceleration means how much the speed changes each

second.


25. Explain if it is possible for a bicycle have a greater acceleration away from lights than a car?

It is possible (briefly).

The smaller mass of the bike could allow the cyclist

to make it speed up at a quicker rate than the car for

the first second or two.


26. Car performance figures for "Feline Cars Ltd" are shown in the table.

(a) Which model has thegreatest acceleration?

(c) The top speed of the Cheetah is 180 mph. At maximum acceleration, what time will it take to reach this speed?

Feline Cars:Model

Cheetah

Leopard

Panther

Lion

Tiger

Time in seconds(0 - 60 mph)

5.4

6.2

6.8

8.1

8.5

the Cheetah

(b) After 5 seconds, approximately how fast will the Leopard be travelling?approx 50 mph

16 to 17 seconds


27. A football player is practising taking penalty kicks.

Explain why the ball travels faster when the player is

running when he strikes the ball than when he isstanding still.When the player is running, his foot is movingforward faster when it collides with the ball,and so the force on the ball is greater.


28. In the World Cup competition in France in 1998, a lighter ball was introduced.Explain why this ball travelled faster than the older ball even though it was kicked exactly the same way.In a collision, the change in speed is greater

when themass is smaller.


29. In a schools competition, called "Braking Without Breaking" competitors have to find a way of dropping an egg from the ceiling to the floor without breaking the egg.

To avoid breaking the egg, you need to stop it with as

small a force as possible.

Devise a possible solution. Explain your solution.

This means it has to be stopped in as big a distance

as possible;for example, by dropping it into a thick pile of cotton

wool/tissue paper etc.


30. John's father is a bricklayer. When John was watching his father at work, he noticed that his father's hand moved backwards when he caught a brick thrown to him by his workmate. John remembered that when his father caught the ball when playing table tennis, his hand did not move backwards. Explain this difference.The table tennis ball has a small mass and its

speed ischanged easily in a short distance.The brick has a much larger mass and its speed

ismore difficult to change, needing a bigger

distance.


31. Why are golf balls made to be so hard and clubs made of iron or hard wood?

The hard surfaces ensure that more of the energy of

the club is transferred to the ball during thecollision; making it go as fast as possible.


32. Padder Tennis is a popular indoor game using bats and sponge balls. What is the point of using a sponge ball?The soft surfaces ensure that less energy istransferred to the ball - so it goes slowly.


33. A golf ball is dropped onto a concrete floor and another dropped into a sand tray.Which rebounds higher and why?

The one dropped on to the concrete rebounds higher,because the hard concrete absorbs only a little of

the ball’s energy.(The soft sand absorbs more of the ball’s energy.)


34. Two tennis rackets are securely clamped. One is old and needs restrung as the strings have stretched, the other is new. Tennis balls are dropped onto each from the same height.

The ball dropped on to the new racket (with the tight

strings) rebounds higher,because the tighter

stringstransfer more of the energy back to the ball.

Explain which will bounce higher and why.


35. Two pupils want to find out if altering the speed of launch changes the range.The table below shows the results.

The greater the speed of launch, the greater the range.

(a) What conclusion can the students make?

Speed of Launch(m/ s)

10

20

30

40

50

Range(m)

8.6

34.6

58.5

138.6

216.5

The angle of launch, the object (mass and shape) being launched.

(b) What would the students need to keep constant to make the experiment fair?


Intermediate 1 Physics Movement

End ofQuestions and

Answers

Beath High School - Int 1 Physics1 Intermediate 1 Physics Movement Questions and Answers.

Documents

beath high school int

force of friction play

motion friction

n slide

ice slide

mass of susan

air resistance slide

mass x g