# Topic 1 & 2 Forces & Motion Flashcards Preview

## Edexcel GCSE Combined Science Physics > Topic 1 & 2 Forces & Motion > Flashcards

Flashcards in Topic 1 & 2 Forces & Motion Deck (82)
1
Q

Runner A finishes a race in less time than runner B. Who is faster?

A

Runner A

2
Q

What two measurements are needed to calculate speed?

A

distance and time

3
Q

What is the SI unit for speed?

A

m/s

4
Q

What does acceleration mean?

A

speeding up or slowing down

5
Q

What is a force?

A

push or pull

6
Q

How do we represent forces on diagrams?

A

arrows, with length depending on size of force

7
Q

What does mass mean?

A

amount of substance

8
Q

What is the unit for mass?

A

kilogram

9
Q

What does a vector have that a scalar does not?

A

direction

10
Q

Name a scalar and a vector measured in metres.

A

distance, displacement

11
Q

Name a scalar and a vector measured in metres/second.

A

speed, velocity

12
Q

Name a vector with units of newtons.

A

force or weight

13
Q

Is mass a vector or scalar?

A

scalar

14
Q

Is energy a vector or scalar?

A

scalar

15
Q

What is acceleration?

A

a change in velocity

16
Q

Why is acceleration a vector?

A

it is measuring a change in another vector

17
Q

What is the difference between speed and velocity?

A

velocity has a direction/is a vector

18
Q

What is the equation for calculating speed?

A

speed = distance / time

19
Q

What is the SI unit for speed?

A

metres per second

20
Q

What is the equation for average speed?

A

total distance / time for whole journey

21
Q

What is the equation for calculating distance?

A

distance = speed x time

22
Q

How is a constant speed shown on a distance/time graph?

A

straight, sloping line

23
Q

What does a horizontal line on a distance/time graph show?

A

stationary object

24
Q

What is the speed of sound in air?

A

approximately 330m/s

25
Q

How is a stationary object shown on a distance/time graph?

A

horizontal line

26
Q

How can you tell which part of a journey shown on a distance/time graph has the highest speed?

A

steepest line

27
Q

How can you calculate velocity from a distance/time graph?

A

28
Q

What does acceleration mean?

A

change in velocity in time

29
Q

What are the units for acceleration?

A

metres per second squared

30
Q

In the acceleration equation, what does u stand for?

A

initial velocity

31
Q

In the acceleration equation, what does v stand for?

A

final velocity

32
Q

What is the equation for calculating acceleration?

A

change in velocity/time

33
Q

What is the acceleration due to gravity?

A

10m/s2 to 1 sig. fig or 9.8m/s2 to 2 sig. fig.

34
Q

What is the force that pulls us towards the Earth?

A

gravity

35
Q

What is ‘drag’ another name for?

A

air resistance or water resistance

36
Q

What are balanced forces?

A

forces of the same size in opposite directions

37
Q

What do we call the forwards force produced by an aeroplane’s engine or propeller?

A

thrust

38
Q

What word describes both the speed and direction of movement of an object?

A

velocity

39
Q

What is the name for a single force on an object with the same effect as all the forces combined?

A

resultant

40
Q

How do we describe the forces on an object when the force in one direction is bigger than the force in the other?

A

unbalanced

41
Q

Two forces on an object are in the same direction. How do we calculate the resultant force?

A

42
Q

Two forces on an object are in opposite directions. How do we calculate the resultant force?

A

find the difference between them

43
Q

What does the length of a force arrow on a diagram represent?

A

size of force

44
Q

An aeroplane has thrust of 2000N and drag of 1800N. What is the resultant?

A

200N forwards

45
Q

Air resistance on a cyclist is 20N and friction is 5N. What is the total force trying to slow the cyclist down?

A

25N backwards

46
Q

Name a vector quantity that changes as a car drives at constant speed around a roundabout.

A

velocity

47
Q

What are unbalanced forces?

A

forces of different sizes in opposite directions

48
Q

What is the direction of the resultant force on a car that is speeding up?

A

forwards

49
Q

What is the direction of the resultant force on a bicycle that is slowing down?

A

backwards

50
Q

How does a sideways resultant force affect the velocity of a moving object?

A

changes its direction

51
Q

How can the pilot of an aeroplane make the plane gain speed upwards?

A

increase the lift/upwards force

52
Q

How do balanced forces affect the velocity of a moving car?

A

The car continues with the same velocity.

53
Q

You pedal harder on a bicycle. What happens?

A

you accelerate/get faster

54
Q

What is the name of the force that makes objects move in a circular path?

A

centripetal

55
Q

What provides the centripetal force for a car going around a roundabout?

A

friction

56
Q

What are the forces on a moon orbiting around a planet?

A

gravity acting towards the planet

57
Q

In which direction does centripetal force act?

A

towards the centre of the circle .

58
Q

Why is the force of gravity greater on a lorry than on a car?

A

larger mass

59
Q

Why is the resultant force accelerating a car usually less than the force provided by its engine?

A

air resistance and/or friction

60
Q

Name one force that usually has to be taken into account when working out the resultant force on a moving object

A

drag or friction

61
Q

When will a resultant force act to slow a car down?

A

when backwards forces are greater than forwards ones

62
Q

How can friction act to make a car speed up?

A

63
Q

How can friction act to make a car slow down?

A

in brakes

64
Q

What is the formula linking force, mass and acceleration?

A

F = m x a

65
Q

An object is moving at a constant velocity. What can you say about the forces on it?

A

balanced

66
Q

What is the equation relating to constant velocity?

A

speed = distance / time

67
Q

What type of force is used to slow down a moving vehicle?

A

friction

68
Q

Where is this force applied?

A

brakes, tyres

69
Q

Why is a wet road more slippery than a dry one?

A

water acts as lubricant

70
Q

An object has a negative acceleration. What does this mean?

A

it is slowing down

71
Q

What effect does drinking alcohol have on human reaction times?

A

slows them down/makes them longer

72
Q

How will being tired affect reaction time?

A

make it longer

73
Q

What does braking distance mean?

A

the distance a car travels while slowing down

74
Q

What does thinking distance mean?

A

the distance a car travels while the driver is reacting to a danger and deciding to apply the brakes

75
Q

How does speed affect the thinking distance?

A

higher speed, longer thinking distance/thinking distance directly proportional to speed

76
Q

How does speed affect the braking distance?

A

higher speed, longer braking distance/braking distance proportional to speed squared

77
Q

How does the force needed for an acceleration depend on the size of the acceleration?

A

larger acceleration, larger force needed

78
Q

What does deceleration mean?

A

slowing down/a negative acceleration

79
Q

What factors affect the momentum of a moving object?

A

mass, velocity

80
Q

How does the mass affect momentum?

A

higher mass, higher momentum

81
Q

How does the velocity affect momentum?

A

higher velocity, higher momentum

82
Q

What does momentum is conserved mean?

A

total momentum is the same before and after a collision