Forces- Physics Paper 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What does a vector quantity have?

A

A magnitude and a direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does a scalar quantity have?

A

Just a magnitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are examples of vector quantities?

A

force, velocity, displacement, acceleration, momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are examples of scalar quantities?

A

speed, distance, mass, temperature ,time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a force?

A

A push or a pull that acts on an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the unit of force?

A

Newtons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What’s a Contact force ?

A

a force that acts between two objects that are physically touching each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What’s a non contact force?

A

forces that act between two objects that are not physically touching each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are examples of contact forces?

A

Reaction force, Tension, Friction, Air resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are examples of non-contact forces?

A

Magnetic force, Electrostatic force, gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an interaction pair?

A

A pair of forces that are equal and opposite and act on 2 interacting objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is weight?

A

The force acting on an object due to gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is mass?

A

The amount of matter in an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is weight measured in?

A

Newtons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the centre of mass?

A

The point at which the whole mass of an object is concentrated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do you measure weight?

A

Using a newton meter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the equation for weight?

A

Weight = mass X gravitational field strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the equation for work done?

A

Work done = force X distance moved in the direction of the force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the resultant force?

A

The sum of all the forces acting on an object overall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does a free body diagram show?

A

the forces acting on an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do the arrows on the free body diagram represent?

A

The different forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do the direction of the arrows on a free body diagram show?

A

The direction of the forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What do the lengths of the arrows on a free body diagram represent?

A

The size/magnitudes of the forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What happens if all the forces acting on an object give a resultant force of 0?

A

The forces are balanced and the object is in equilibrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is meant by resolving a force?

A

splitting the force into 2 component forces that are at right angles to each other. The combination of the 2 forces has the same effect as the original single force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is work done?

A

The energy transferred when a force moves an object through a distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is elastic deformation?

A

When an object can go back to its original shape and length after the force has been removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is inelastic deformation?

A

When an object doesn’t return back to its original shape and length when the force has been removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are objects that can be elastically deformed called?

A

Elastic objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the extension of a stretched spring directly proportional to?

A

The load of the force applied

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is Hooke’s law?

A

force = spring constant × extension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the Limit of proportionality?

A

The limit of proportionality refers to the point beyond which Hooke’s law is no longer true when stretching a material. The elastic limit of a material is the furthest point it can be stretched or deformed while being able to return to its previous shape.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What happens once a material has gone past its elastic limit?

A

its deformation is said to be inelastic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The higher the spring constant….

A

the stiffer the spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is a moment?

A

The turning effect of a force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the equation for a moment?

A

moment of a force = force × perpendicular distance from the line of action of the force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a moment measured in?

A

newton-metres (Nm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What do levers do?

A

They make it easier for us to do work i.e lift an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why do levers mean less force is needed to get to the same moment?

A

Because levers increase the distance from which the force is applied

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

If an object is balanced, the total clockwise moment about a pivot is equal to…

A

the total anticlockwise moment about that pivot.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What does a lever consist of?

A

a pivot, an effort, a load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Why are levers force multipliers?

A

Because they increase the effect of the force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are gears?

A

wheels with toothed edges that rotate on an axle or shaft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Will a larger gear turn slower than a smaller gear?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What happens when 2 gears meet?

A

the teeth must both move in the same direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

The forces acting on the teeth of gears are identical but their what are different?

A

Their moments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

If the driven gear is made larger it will rotate more slowly but with a greater or smaller moment?

A

a greater moment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

If the driven gear is made smaller it will rotate more quickly but with a greater or smaller moment?

A

smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is pressure?

A

Force per unit area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is a fluid?

A

Substances that can ‘flow’ because their particles are able to move around

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What do fluids include?

A

Liquids and gases

52
Q

What is the equation for pressure?

A

pressure = force / area

53
Q

What is pressure measured in?

A

pascals

54
Q

What is the equation for pressure in a liquid?

A

pressure = height of column × density of the liquid × gravitational field strength

55
Q

What affects the pressure in a liquid?

A

The density of the liquid and the depth of the liquid

56
Q

If a liquid becomes very dense, what will happen to the pressure?

A

The pressure will increase.

57
Q

Why does liquid pressure increase with depth?

A

Because as the depth increases, the number of particles above that point increases. The weight of these particles adds to the pressure experienced a that point so the liquid pressure increases with depth.

58
Q

What is the atmosphere?

A

The layer of air that surrounds the earth

59
Q

What is atmospheric pressure created by?

A

air molecules colliding with a surface

60
Q

What happens to atmospheric pressure when altitude increases?

A

Atmospheric pressure decreases

61
Q

What 2 factors cause atmospheric pressure to decrease when altitude increases?

A

Density, and how much air there is above a certain point

62
Q

Why does density cause atmospheric pressure to decrease when altitude increases?

A

Because as altitude increases, the atmosphere gets less dense. This means that there air fewer air molecules that are able to collide with a surface, which in turn means a lower atmospheric pressure.

63
Q

Why does how much air there is above a certain point cause atmospheric pressure to decrease?

A

Because an increasing altitude means fewer air molecules above a surface. This means that the weight of the air above, which contributes to atmospheric pressure, decreases.

64
Q

What is the upthrust?

A

The upward force exerted by a liquid or a gas on an object floating in it

65
Q

What is the upthrust equal to?

A

The weight of the fluid that has been displaced by the object

66
Q

What happens if the upthrust of an object is equal to or larger than the object’s weight?

A

The force balances and the object floats

67
Q

What happens when the upthrust is less than the weight of the object?

A

The object will sink

68
Q

Why does an object that is less dense than the fluid it’s placed in float?

A

Because the object weighs less than the equivalent volume of fluid. This means that it displaces a volume of fluid that is equal to its weight before it can become completely submerged. At this point, the upthrust is equal to the object’s weight so the object floats.

69
Q

Why does an object that is denser than the fluid it’s placed in float?

A

Because the object weighs more than the equivalent volume of fluid. This means that it is unable to displace enough fluid to equal its weight. As its weight is larger than the upthrust, the object sinks.

70
Q

What type of quantity is distance?

A

A scalar quantity

71
Q

What type of quantity is displacement?

A

A vector quantity

72
Q

What does displacement measure?

A

The distance and direction in a straight line from an object’s starting starting point to finishing point.

73
Q

What type of quantity is speed?

A

A scalar quantity

74
Q

What type of quantity is velocity?

A

A vector quantity

75
Q

What speed does an object moving in a circle have?

A

A constant speed

76
Q

What happens to the direction of an object moving in a circle?

A

It always changes

77
Q

What can affect the speed something travels at?

A

age
terrain
fitness
distance travelled

78
Q

What is speed?

A

Speed is the rate of change of distance - it is the distance travelled per unit time.

79
Q

What is the speed of walking?

A

1.5 m/s

80
Q

What is the speed of running?

A

3 m/s

81
Q

What is the speed of cycling?

A

6 m/s

82
Q

What is the speed of a car ?

A

13 m/s - 30m/s

83
Q

What is the speed of a train?

A

50 m/s

84
Q

What is the speed of an aeroplane?

A

250 m/s

85
Q

What is the acceleration?

A

How quickly the velocity is changing

86
Q

How can acceleration be calculated?

A

the change in velocity/ time taken

87
Q

What is the equation for uniform acceleration?

A

final velocity squared - initial velocity squared = 2 X acceleration X distance

88
Q

What is the gradient of a distance-time graph equal to?

A

The speed

89
Q

The steeper a distance-time graph…

A

the faster it’s going

90
Q

What goes on the horizontal axis of a velocity-time graph?

A

The time in seconds

91
Q

What goes on the vertical axis of a velocity-time graph?

A

The velocity in m/s

92
Q

What does the gradient of a velocity-time graph tell you?

A

The acceleration of the object

93
Q

What are the 2 main ways of changing a vehicle to increase its top speed?

A

1) Reducing drag by altering the shape of the vehicle to make it more streamlined.
2) Increasing the power of the vehicle’s engine so that the driving force becomes larger and so the drag force on the vehicle will equal the driving force at a higher speed.

94
Q

What is terminal velocity?

A

the decrease in the speed of an object till it reaches a steady velocity

95
Q

What are the 3 stages of falling?

A

1) at the start, the object accelerates downwards due to the force of gravity
2) as the object’s speed increases, frictional forces such as air resistance or drag increase
3) at terminal velocity, the weight of the object due to gravity is balanced by the frictional forces, and the resultant force is zero

96
Q

What factors affect terminal velocity?

A

the objects shape and the objects area

97
Q

What is Newton’s first law?

A

an object remains in the same state of motion unless a resultant force acts on it.

98
Q

What happens when the resultant force on a stationary object is zero?

A

The object will remain stationary

99
Q

,

A

.

100
Q

What different forms can changing velocity take place in?

A

starting, stopping, changing direction, speeding up, slowing down

101
Q

What is inertia?

A

When an object will remain stationary , or continue at the same velocity, unless a resultant force is applied

102
Q

What is Newton’s second law?

A

The acceleration of an object is directly proportional to the resultant force acting on the object and inversely proportional to the mass of the object.

103
Q

What is the equation for resultant force?

A

Resultant force = mass X acceleration

104
Q

What is acceleration measured in?

A

m/s^2

105
Q

What is the equation for inertial mass?

A

inertial mass = resultant force/ acceleration

106
Q

What is Newton’s third law?

A

whenever two objects interact, they exert equal and opposite forces on each other.

107
Q

If you push a shopping trolley, what does the shopping trolley do to you?

A

Push back against you, just as hard

108
Q

What is the equation for stopping distance?

A

stopping distance = thinking distance + braking distance

109
Q

What is the thinking distance?

A

thinking distance is the distance a vehicle travels in the time it takes for the driver to apply the brakes after realising they need to stop

110
Q

What is the braking distance?

A

braking distance is the distance a vehicle travels in the time after the driver has applied the brake

111
Q

What factors affect the thinking distance?

A

How fast you’re going and how quick you are to respond

112
Q

What affects the braking distance?

A

How good your brakes are, how good the tyres are, how fast you’re going, how good the grip is

113
Q

What is the correlation between speed and thinking distance?

A

They’re directly proportional

114
Q

.

A

.

115
Q

What is momentum?

A

A property of moving objects

116
Q

What quantity is momentum?

A

a vector quantity - this means it has both a magnitude and an associated direction.

117
Q

How do you calculate momentum?

A

momentum = mass X velocity

118
Q

What are the units of momentum?

A

kg m/s

119
Q

What are the units of velocity?

A

m/s

120
Q

What is the conservation of momentum?

A

The idea that in a closed system, the momentum before an event is the same as the momentum after an event

121
Q

What is the equation for changes in momentum?

A

force = change in momentum/change in time

122
Q

What decreases the rate of change of momentum, which decreases the force of the collision on any people within the car?

A

Crumple zones, seat belts and air bags

123
Q

What is the force normal?

A

the force that particles exert at right angles to a surface

124
Q

Where is pressure the highest in the sea?

A

At the bottom because there’s more water above the diver and the weight of the water on the diver is higher

125
Q

What is the speed of sound in air?

A

330 m/s

126
Q

Do objects that are not moving having momentum?

A

No, only objects that are moving