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# GCSE MOTION

## Force & Motion

Name & Set
A sky-diver jumps from an aeroplane. Here is a velocity-time graph to show the descent to the
ground in a simplified form

80

60

40

20
D
C

0
0

10

20

30

40

50

60
Time / s

## (a) In section OA of the graph, what is

(i) the maximum velocity reached? __________________________________________________ [1]
(ii) the time taken? ______________________________________________________________ [1]
(iii) the acceleration of the sky-diver
______________________________________________________________________________
___________________________________________________________________________ [1]
(iv) the vertical distance that the sky-diver free falls?
______________________________________________________________________________
___________________________________________________________________________ [2]
(b) In section AB, the sky-diver has reached terminal velocity.
(i) Why does the velocity remain constant?
______________________________________________________________________________
___________________________________________________________________________ [1]
(ii) What distance does the sky-diver fall at constant velocity?
______________________________________________________________________________
___________________________________________________________________________ [2]

GCSE MOTION
(c) At B, the sky-diver opens the parachute and decelerates rapidly.
(i) What is the deceleration of the sky-diver?
______________________________________________________________________________
___________________________________________________________________________ [2]
(d) why is the sky-diver again at constant velocity in the section CD of the graph?
______________________________________________________________________________
___________________________________________________________________________ [1]
(e) What happens to the sky-diver at D?
___________________________________________________________________________ [1]
2

(i)

(a) A car made a short journey. Some information about the journey is given in the table.
Time taken in
seconds (s)

Distance travelled
in metres (m)

50

300

100

800

150

1400

200

2200

250

3400

300

5000

Complete the graph by labelling each axis, plotting the points, drawing a smooth curve through
the points

5000

4000

3000

2000

1000

0
0

50

100

150

200

250

300

GCSE MOTION
(ii) How can you tell, from your graph, that the speed of the car was greater in the second half of the
journey than in the first half of the journey?
_________________________________________________________________________________
______________________________________________________________________________ [2]
(iii) Calculate the average speed of the car during the journey. Include in your answer the equation
you are going to use. Show clearly how you get to your final answer and give the unit.
_________________________________________________________________________________
______________________________________________________________________________ [4]
(b) Name three forces that act on the car when it is moving along the road.
Force 1 ________________________________________________________________________ [1]
Force 2 ________________________________________________________________________ [1]
Force 3 ________________________________________________________________________ [1]

GCSE MOTION
3

The diagram shows an orbiter, the reusable part of a Space Shuttle. The data refers to a typical
flight.
Orbiter data
Mass
Orbital speed

78 000 kg
7.5 km/s

Orbital altitude

200 km

Landing speed

100 m/s

Flight time

7 days

(a) (i) What name is given to the force which keeps the orbiter in orbit around the Earth?
______________________________________________________________________________ [1]
(ii) Use the following equation to calculate the kinetic energy, in joules, of the orbiter while it is in
orbit.
kinetic energy = 1

mv 2

_________________________________________________________________________________
______________________________________________________________________________ [2]
(iii) What happens to most of this kinetic energy as the orbiter re-enters the Earth's atmosphere?
_________________________________________________________________________________
______________________________________________________________________________ [1]
(b) After touchdown the orbiter decelerates uniformly coming to a halt in 50 s.
(i) Give the equation that links acceleration, time and velocity.
______________________________________________________________________________ [1]
(ii) Calculate the deceleration of the orbiter. Show clearly how you work out your answer and give the
unit.
_________________________________________________________________________________
______________________________________________________________________________ [2]
(c) (i) Give the equation that links acceleration, force and mass.
______________________________________________________________________________ [1]
(ii) Calculate, in newtons, the force needed to bring the orbiter to a halt. Show clearly how you work
_________________________________________________________________________________
______________________________________________________________________________ [1]

GCSE MOTION
4

The table shows the braking distances for a car at different speeds and kinetic energy. The
braking distance is how far the car travels once the brakes have been applied.
Braking distance
of car in m.

Speed of car
in m/s.

Kinetic energy
of car in kJ

10

40

12

15

90

20

20

160

33

25

250

45

30

360

Kinetic energy in kJ

(a) A student suggests, "the braking distance is directly proportional to the kinetic energy."
(i) Draw a line graph to test this suggestion.

Braking distance in m

GCSE MOTION
(ii) Does the graph show that the student's suggestion was correct or incorrect? Give a reason for your
_________________________________________________________________________________
______________________________________________________________________________ [1]
(iii) Use your graph and the following equation to predict a braking distance for a speed of 35 metres
per second (m/s). The mass of the car is 800 kilograms (kg). Show clearly how you obtain your
kinetic energy = 1

mv 2

_________________________________________________________________________________
______________________________________________________________________________ [2]
(iv) State one factor, apart from speed, which would increase the car's braking distance.
______________________________________________________________________________ [1]
(b) The diagram shows a car before and during a crash test. The car hits the wall at 14 metres per
second (m/s) and takes 0.25 seconds (s) to stop.

After
Before

(i) Write down the equation that links acceleration, change in velocity and time taken.
______________________________________________________________________________ [1]
(ii) Calculate the deceleration of the car.
______________________________________________________________________________ [1]
(iii) In an accident the crumple zone at the front of a car collapses progressively. This increases the
time it takes the car to stop. In a front end collision the injury to the car passengers should be
reduced. Explain why. The answer has been started for you.
By increasing the time it takes for the car to stop, the ______________________________________
_________________________________________________________________________________
______________________________________________________________________________ [2]

GCSE MOTION
6

(a) The following table gives the total kinetic energy of a car, and the passengers inside it, at
different speeds.
Speed in metres/second (m/s)

10

15

20

25

30

35

## kinetic energy in kilojoules (kJ)

10

40

90

160

250

360

490

(i) Use part of this information to calculate the total mass of the car and its passengers.
Write down the equation you are going to use.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [4]
(ii) Plot a graph of speed (on the x-axis) against kinetic energy (on the y-axis).
(a) Label each of the axes.
(b) Draw a smooth curve for the correct points.

[2]
[1]

500

400

300

200

100

0
0

10

15

20

35

25

30

(iii) The speed limit in built up areas is 13 m/s. Use the graph to estimate the kinetic energy of the car
and passengers at this speed.
______________________________________________________________________________ [2]

GCSE MOTION
(iv) Use the graph to find out what increase in speed would be needed for the car and passengers to
have double the kinetic energy which they had at 13 m/s.
______________________________________________________________________________ [2]
(v) What happens to most of the kinetic energy of a car when the brakes are applied?
______________________________________________________________________________ [1]
(b) (i) What is the braking distance of a car?
______________________________________________________________________________ [1]
(ii) Explain what the connection is between the braking distance of car and its speed
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [4]
7
The diagram shows the path of a ball when thrown through the air.
(i) Add to the diagram the name and direction of the force or forces acting on the ball in the three
positions shown. Assume that position 1 corresponds to the point immediately after release and that
during the whole flight air resistance is negligible
[2]

(ii) Explain, in terms of the energy changes of the ball, why the ball reaches a maximum height.
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [3]
(iii) If the ball had been thrown with the same velocity on the moon, describe and explain how the
path of the ball would be changed.
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [3]

GCSE MOTION
(a) The following graph shows the speed of a car at different times during a short journey.

## Speed in metres per second (m/s)

40

30

20

10

0
0

10

20

30
40
50
60
70
Time from the start in seconds (s)

(i) What additional information would you need in order to know the velocity of the car?
______________________________________________________________________________ [1]
(ii) During part of its journey the car was travelling at a steady speed.
Calculate the distance that the car travelled during that part of its journey. Include in your answer the
equation you are going to use. Show clearly how you get to your final answer and give the unit.
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [4]
(iii) During part of its journey the car was slowing down.
Calculate the deceleration of the car during that part of its journey. Include in your answer the
equation you are going to use. Show clearly how you get to your final answer and give the unit.
_________________________________________________________________________________
______________________________________________________________________________ [4]
(b) Later the car accelerates at 2.5 metres per second per second (m/s2).
The mass of the car is 800 kilograms (kg).
Calculate the force needed to accelerate the car. Include in your answer the equation you are going to
use. Show clearly how you get to your final answer and give the unit.
_________________________________________________________________________________
______________________________________________________________________________ [3]
(c) The car driver and passengers wear seatbelts. Explain how a seatbelt reduces the risk of injury if
a car stops suddenly. You should include ideas about acceleration and force in your explanation.
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [4]

GCSE MOTION
9

A space shuttle orbits the earth 700 km above the surface at a speed of 7500m/s. To return to
Earth falls out of orbit. It has no engine for most of its descent it glides. A few minutes later it
lands on the ground at a speed of 100 m/s.

7500 m/s

glide path

70

km
orbit
Earth

## (a) What energy changes take place during the descent?

________________________________________________________________________________
_____________________________________________________________________________ [2]
(b) What percentage of its energy in orbit is left at touch-down?
(You dont have to know the actual mass of the shuttle to work this out.)
________________________________________________________________________________
_____________________________________________________________________________ [2]
10

## (a) A rocket is travelling through space at a constant velocity of 2000 ms-1.

State what forces act on it.

______________________________________________________________________________ [1]
(b) The rockets motor is fired in a direction opposite to that of its motion for 10 s.
Explain what happens to its velocity and explain why.
_________________________________________________________________________________
______________________________________________________________________________ [2]
(c) The force on the rocket is 20 kN.
If the mass of the rocket is 1000 kg, calculate its acceleration during the 10 s period.
_________________________________________________________________________________
______________________________________________________________________________ [3]
(d)Calculate the final velocity of the rocket after the motors have been turned off.
_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [4]

10

GCSE MOTION
11

An aeroplane must reach a velocity of 100 m/s before it can take off. Starting from rest it
accelerates down the runway at a uniform rate. It takes 25 seconds to become airborne.

(a) Use this information to plot a velocity time graph for the aeroplane during take-off.

## (b) What is the acceleration of the plane?

______________________________________________________________________________
___________________________________________________________________________ [2]
(c) How far has the plane travelled along the runway before it gets airborne?
______________________________________________________________________________
___________________________________________________________________________ [2]

11

GCSE MOTION
11

## A jet aircraft is taking off from an airport.

Its mass, including passengers and fuel is 150,000 kg. Its take-off speed is 100 ms-1.
The maximum thrust of its engines is 500,000 N.

(a)

## Calculate the kinetic energy of the aircraft at the moment of take-off.

_________________________________________________________________________________
_________________________________________________________________________________
______________________________________________________________________________ [2]
(b)

## Name the two main forces acting on the plane at take-off.

_________________________________________________________________________________
______________________________________________________________________________ [2]
(c)
We can assume there are no forces of resistance and the engines maintain maximum thrust.
Using the equation
Work done (joules) = force x distance
Calculate the minimum length of runway needed for take-off.
_________________________________________________________________________________
______________________________________________________________________________ [3]
(d)

The following forces act on an aircraft when it is in flight: weight, drag, lift and thrust. On the
diagram below draw labelled arrows to show the size and direction of these forces when a plane
is travelling at constant speed and constant height above the ground.
[4]

Describe what will happen to the speed and height of the plane if the trust of the engines is reduced?
_________________________________________________________________________________
______________________________________________________________________________ [1]
Describe what will happen to the speed and height of the plane if the lift of the wings is reduced?
_________________________________________________________________________________
______________________________________________________________________________ [1]

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