Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics 9-1 iGCSE Oxford AQA > Forces > Flashcards

Forces Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What do vector quantities have?

A

Magnitude and Direction

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

What are vector qualities usually repented by?

A

Arrow

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

What does the length of the arrow represent (vector)?

A

Magnitude

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

What does the direction of the arrow represent (vector)?

A

Direction of quantity

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

What are scalar quantities?

A

Have magnitude (and no direction)

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

What can a force be? (name three things)

A
  • Pull
  • Push
  • Twist
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a force?

A

Push or pull on object caused by it interacting with something

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

What is an interaction pair?

A

Pair of forces that are equal and opposite and act on two interacting objects

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

What 2 important effects does gravity have?

A
  1. On the surface, it makes all things fall towards the ground
  2. Gives everything a weight
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is weight?

A

Force acting on an object due to gravity

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

What does the weight of an object depend on?

A

Strength of gravitational field at location

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

When is the gravitational field strength stronger? (name 2 scenarios)

A
  1. Stronger for larger masses

2. Stronger the closer you are to mass causing field

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

What is mass?

A

Amount of “stuff” in an object

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

Mass and weight are…

A

Directly Proportional

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

What do free body diagrams show?

A

All the forces acting on an object

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

What is a resultant force?

A

Overall force on a point or object

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

When is work done?

A

When a force moves an object through a distance, energy is transferred and work is done on the object

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

When you apply force on a object, what may happen? (name 3 things)

A

It may stretch, compress or bend

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

To stretch, compress or bend an object, what is needed & why?

A

More than one force is needed, otherwise it’ll go in direction of force applied

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

When a force stretches or compresses an object, what is done and why?

A

Work is done because the force causes energy to be transferred to elastic potential energy store of object

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

An object that is elastically deformed can…

A

Go back to its original shape and length after force is removed

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

What type of objects can be elastically deformed?

A

Elastic objects

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

When an object is elastically deformed, what happens to the energy?

A

ALL energy (from force) is transferred object’s elastic potential energy store

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

An object that’s inelastically deformed will…

A

Its shape will change permanently (when force is removed)

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

What is Hooke’s law?

A

Extension of an object is directly proportional to force applied to it, provided that the limit of proportionality is not exceeded

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

What does the spring constant (k) depend on?

A

Material being stretched

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

The stiffer the spring…

A

The greater the spring constant

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

What is the limit of proportionality?

A

When the extension is no longer proportional to force

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

What type of quantity is distance?

A

Scalar

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

What type of quantity is displacement?

A

Vector

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

What does displacement measure?

A

Measures distance and direction in a straight line form object’s starting point to its finishing point

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

What type of quantity is speed?

A

Scalar

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

What type of quantity is velocity?

A

Vector

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

What is the difference between speed and velocity?

A
  • Speed is how fast you’re going

- Velocity is speed in a given direction

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

Can objects can travel at a constant speed with a changing velocity & why?

A

Yes, object changes direction but remains at same speed e.g. car going around a roundabout

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

What is acceleration?

A

The change in velocity in a certain amount of time

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

Can an object accelerate by changing its direction even if it’s going at constant speed?

A

Yes

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

What is deceleration essentially?

A

Negative acceleration i.e. when something slows down, change in velocity is negative

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

What is centre of mass?

A

Point at where the whole mass is concentrated

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

For a uniform shape, where will gravity act from?

A

At the centre of the object

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

What does the position of centre of mass affect?

A

The stability of objects

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

How can you finding centre of mass with an irregular shape?

A
  1. Hang the irregular shape (e.g. card) from a rod secured onto a clamp stand
  2. Use a plumbline (string with weight on the end) to draw vertical line on card from rod downwards
  3. Repeat procedure with card suspended from 2nd & 3rd point to give another similar line
  4. Centre of mass of card is where lines meet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

If a card is at rest, freely suspended from a rod, where will its centre of mass be?

A

Directly below rod

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

If the line from the centre of mass is within a base of a titling object, what will happen to the object?

A

Will not topple

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

If the line from the centre of mass is outside a base of a titling object, what will happen to the object?

A

There’ll be a resultant moment and it will topple

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

How can you make an object (e.g. a stool) more stable?

A
  1. Make it wider

2. Make it closer to the ground

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

How can you increase the momentum of an object?

A

Increase the mass of object OR its velocity

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

What is a closed system?

A

When no external forces can act

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

What is meant by momentum is conversed?

A

Closed System: Momentum before event = Momentum after event

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

In an explosion, what is the momentum before and after the event?

A

0

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

Why is the momentum after an explosion 0?

A

Pieces fly off in different directions = total momentum cancels out to 0

52
Q

What causes a change in momentum?

A

Forces

53
Q

The larger the force… (momentum)

A

the faster the change in momentum

54
Q

Why does a car crash cause injury?

A

Bc person’s momentum changes very quickly = forces on body will be very large + cause injury

55
Q

Why are cars designed to slow people down over a longer time when they crash?

A

Longer it takes for a change in momentum = smaller the rate of change of momentum = smaller force = injuries less severe

56
Q

Name 3 safety features cars have

A
  1. Air bags
  2. Crumple zones
  3. Seat belts
57
Q

How do air bags help you in a car crash?

A

Air bags inflate before you hit the dashboard of car = compressing air inside, slows you down more gradually than if you had just hit the hard dashboard

58
Q

How do crumple zones help you in a car crash?

A

Crumple zones crumple on impact = increasing time taken for car to stop

59
Q

How do seat belts help you in a car crash?

A

Seat belts stretch slightly = increasing time taken for wearer to stop

60
Q

How do crash mats and cushioned playground flooring keep you safe if you fall on them?

A

Increase time taken for you to stop if you fall on them because they’re made from soft, compressible materials

61
Q

Why is it useful to wear a helmet when cycling?

A

Bike helmets contain crushable layer of foam = helps lengthen the time taken for your head to stop in a crash = reducing impact on your brain

62
Q

How do you calculate stopping distance?

A

Thinking Distance + Braking Distance

63
Q

What is stopping distance?

A

Minimum distance that a car can safely stop in

64
Q

What is thinking distance?

A

How far the car travels during the driver’s reaction time

65
Q

What is breaking distance?

A

Distance taken to stop under the braking force

66
Q

Name 4 things that affect breaking distance

A
  1. Weather/Road Surface
  2. Speed
  3. Brakes Condition
  4. Condition of Tyres
67
Q

Explain how the weather/road surface can affect the breaking distance

A

If it’s wet or icy, or there’s leaves or oil on road = there’s less grip (friction) between a vehicle’s tyre and road = means tyres can skid

68
Q

Explain how speed can affect the breaking distance

A

For a given brake force: faster a vehicle travels = longer it takes to stop

69
Q

Explain how the conditions of the brakes can affect the breaking distance

A

If brakes are worn and faulty, they won’t be able to apply as much force as well-maintained brakes, which is dangerous when you need to brake hard

70
Q

Explain how the conditions of the tyres can affect the breaking distance

A

If tyres are bald (don’t have any thread left) then they cannot get rid of water in wet conditions = leads to them skidding on top of the water

71
Q

Name 2 things that affect thinking distance

A
  1. Speed

2. Reaction Time

72
Q

Explain how speed can affect the thinking distance

A

The faster you’re going = the further you’ll travel during the time you take to react

73
Q

Explain how reaction time can affect the thinking distance

A

Longer reaction time = longer thinking distance

74
Q

When you brake, why does the temperature of the brakes increase?

A
  1. When break pedal is pushed = brake pads are pressed onto the wheels = contact causes friction, which causes work to be done
  2. Work done between brakes and wheels transfers energy from kinetic energy stores of wheels to thermal energy stores of brakes
  3. Brakes increase in temperature
75
Q

Why is a greater braking force needed to make a car stop if it is going fast?

A

Faster a vehicle is going = more energy it has in its kinetic store = more work needs to be done to stop it

76
Q

The larger braking force…

A

the larger the deceleration

77
Q

Why are very large decelerations dangerous?

A

Brakes can overheat (don’t work as well) or car could skid

78
Q

What is a moment?

A

The turning effect of a force around a fixed point (called a pivot)

79
Q

How do you increase a moment?

A

Increase the force OR increase the distance

80
Q

Total Clockwise Moments….

A

= Total Anticlockwise Moments (about a pivot)

81
Q

How do levers make it easier for us to do work?

A
  1. Levers increase distance from pivot (where force is applied)
  2. Since M = Fd, means less force is needed to get same moment
  3. Means levers make it easier to do work
82
Q

What are gears?

A

Gears are circular discs with ‘teeth’ around their edges

83
Q

How do gears transmit rotational effects?

A

Their teeth interlock = turning one causes another to turn in opposite direction

84
Q

What are gears used for?

A

Used to transmit the rotational effect of a force from one place to another

85
Q

How can different sized gears can be used to change moment of the force?

A

Force transmitted to large gear = bigger moment as distance to pivot is greater

86
Q

Fill in the blanks…

______ gear will turn slower than a ______ gear

A

Larger gear will turn slower than smaller gear

87
Q

On a distance-time graph, what does the gradient represent?

A

Speed

88
Q

On a distance-time graph, the steeper the gradient…

A

the faster the object is going

89
Q

On a distance-time graph, what does a flat section represent?

A

That an object’s stationary - it’s stopped

90
Q

On a distance-time graph, what does a straight uphill section represent?

A

Traveling at steady speed

91
Q

On a distance-time graph, what does a curve represent?

A

Acceleration or deceleration

92
Q

On a distance-time graph, what does a steepening curve represent?

A

Object’s speeding up (increasing gradient)

93
Q

On a distance-time graph, what does a levelling off curve represent?

A

Slowing down (decreasing gradient)

94
Q

If object’s changing speed (accelerating), how can you can find its speed at that point?

A

By finding of the tangent to the curve at that point

95
Q

On a velocity-time graph, what does the gradient represent?

A

Acceleration

96
Q

On a velocity-time graph, what does a flat section represent?

A

Travelling at steady speed

97
Q

On a velocity-time graph, the steeper the gradient…

A

Greater the acceleration or deceleration

98
Q

On a velocity-time graph what do uphill sections (/) represent?

A

Acceleration

99
Q

On a velocity-time graph what do downhill sections () represent?

A

Deceleration

100
Q

On a velocity-time graph what does a curve represent?

A

Changing acceleration

101
Q

How do you the distance on a velocity-time graph?

A

Area under any section of graph

102
Q

Would gravity make all objects fall at the same rate if it wasn’t for air resistance?

A

Yes

103
Q

What causes things to fall at different speeds?

A

Air resistance

104
Q

Frictional force depends…

A

on object’s shape and area

105
Q

Objects falling through fluids will…

A

reach a terminal velocity

106
Q

When falling objects 1st set off, why do they accelerate?

A

Bc force of gravity is much more than frictional force slowing them down

107
Q

(Terminal Velocity) What gradually reduces acceleration and what does this then lead to?

A

As speed increases, friction builds up until eventually frictional force = accelerating force (resultant force is 0)

108
Q

When the frictional force = the accelerating force, what is this known as?

A

Maximum speed or terminal velocity

109
Q

At terminal velocity, an object will travel at…

A

a steady speed

110
Q

What is Newton’s First Law?

A

A resultant force is needed to make something start moving, speed up or slow down

111
Q

If the resultant force on a stationary object is 0, it will…

A

remain stationary

112
Q

If the resultant force on a moving object is 0, it will…

A

carry on moving at the same velocity (same speed and direction)

113
Q

When does velocity change?

A

If there’s non-zero resultant force acting on object

114
Q

What will a non-zero resultant force on an object always produce?

A

An acceleration (or deceleration) in direction of force

115
Q

Name 5 forms the “acceleration” caused by a non-zero resultant force could be

A
  1. Starting
  2. Stopping
  3. Changing direction
  4. Speeding up
  5. Slowing down
116
Q

What is Newton’s Second Law? (2 things)

A
  1. Acceleration is directly proportional to resultant force

2. Acceleration is inversely proportional to mass of object

117
Q

The larger the resultant force acting on object…

A

The more the object accelerates

118
Q

What is Newton’s Third Law?

A

When two objects interact, the forces they exert on each other are equal (in magnitude) and opposite

119
Q

If you push something (e.g. Trolley), what will the trolley do?

A

The trolley will push back, just as hard

120
Q

What does friction do?

A

Slow things down

121
Q

Friction acts in opposite direction to….

A

movement

122
Q

When do you get friction? (name two scenarios)

A
  1. Between 2 surfaces

2. When object passes `through fluid (drag)

123
Q

What is drag?

A

Resistance you get in a fluid (gas or liquid)

124
Q

What is air resistance?

A

Type of drag: frictional force produced by air acting on moving object

125
Q

What is the best way to reduce drag?

A

Keep object streamlined (object is designed to allow fluid to flow easily across it)

126
Q

As drag increases…

A

speed increases

127
Q

Why a car’s engine at 70 mph have to work much harder to maintain a steady speed than a 30 mph?

A

Car has more friction to work against when travelling at 70

mph than 30 mph

Physics 9-1 iGCSE Oxford AQA (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions