Brainscape's Knowledge GenomeTM

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


See full index

Physics > Forces > Flashcards

Forces Flashcards

1
Q

Give 4 vector quantities.

A
  1. Force
  2. Velocity
  3. Displacement
  4. Momentum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Give 4 scalar quantities.

A
  1. Speed
  2. Distance
  3. Time
  4. Mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an interaction pair?

A

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
4
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
5
Q

2 factors that increase gravitational field strength?

A
  1. getting closer to the mass causing the field
  2. increasing size of the object
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a uniform object?

A

An object which density is the same throughout

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

What is a centre of mass?

A

The point at which all mass of an object is concentrated

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

Give the equation for mass.

A

Mass = weight x gravitational field strength

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

What is mass and weight’s relationship?

A

Directly proportional

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

Give the equation for amount of work done.

A

Work = force x distance

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

What happens when “work is done”

A

A force moves an object and energy is transferred from one source to another

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

Which way do you draw the resultant force on a scale drawing?

A

Tail of the first arrow to head of the last arrow

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

How to find the direction of a resultant force on a scale drawing?

A

Measure the angle at the tails to find a bearing

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

How is equilibrium shown on a scale drawing?

A

The head of the last force should meet the tail of the first force (no resultant force so arrows all go same way)

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

What to do with diagonal forces on a scale diagram?

A

Split them into vertical and horizontal components

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

What does elastically deformed mean?

A

An object has been compressed/ stretched but can return to its original shape/ length

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

What does inelastically deformed mean?

A

An object has been stretched/ compressed but can’t return to its original shape/ length

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

Extension equation?

A

Force = spring constant x extension

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

Relationship between extension and force applied?

A

Directly proportional

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

What is the limit of proportionality for force & extension

A

When force and extension are no longer directly proportional after a maximum force

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

Give the equation for a moment.

A

Moment = force x perpendicular distance from pivot to line of action for force

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

What happens if an anticlockwise moment = clockwise moment?

A

The object won’t turn

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

How do levers make work easier?

A

By increasing perpendicular distance from line of action by force (less force is needed to achieve same moment)

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

What are gears used for?

A

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

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

Equation for pressure at the surface of a liquid?

A

Pressure = Force normal to that force/ area of surface

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

How does density differ in a liquid/gas?

A

In liquid, density is uniform - same everywhere - in a gas it can vary

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

How does density affect pressure on a liquid?

A

The denser a liquid, the higher the pressure as there are more particles in a certain volume, so more collisions happen.

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

How does depth affect a liquid’s pressure?

A

The deeper in a liquid, the more particles above the point, the weight of these particles adds to the pressure

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

What are 2 factors that affect a liquid’s density?

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

Equation for a liquid at a certain depth?

A

Pressure = height of column of liquid (depth) x gravitational field strength x density of liquid

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

What is upthrust equal to?

A

The volume of water which has been displaced by the object

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

What is upthrust?

A

The resultant force which pushes an object upwards if it has been submerged

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

What causes an object to float?

A

If the upthrust is equal to the object’s weight, so the forces balance

34
Q

What causes an object to sink?

A

If the weight is greater than the upthrust

35
Q

Explain how an object floats in terms of density.

A
  • An object that is less dense than the fluid it is in will weigh less than an equal volume of that liquid. – - It displaces a volume of liquid equal to its weight, so the water displaced is less than the object’s volume
  • This means the object sticks out of the water and not fully submerged however the weight is equal to the upthrust so it floats
36
Q

Explain sinking in terms of density?

A

An object denser than the fluid it is in will not be able to displace a volume of water equal to its weight, meaning weight is always greater than upthrust.

37
Q

What is atmospheric pressure?

A

Particles from the air colliding with a surface

38
Q

Why does atmospheric pressure decrease with altitude? (2)

A
  1. There are fewer air molecules and the air is less dense so collisions become rarer
  2. Also there are fewer molecules above you, so weight decreases
39
Q

Equation for speed?

A

Speed = distance/time

40
Q

What is velocity?

A

Speed with a given direction

41
Q

2 factors which can affect walking speed?

A
  1. age
  2. terrain
42
Q

What impacts speed of sound?

A

Medium it travels through

43
Q

What affects windspeed?

A

Large buildings

44
Q

Equation for velocity?

A

Acceleration = change in velocity/ time

45
Q

Average speeds for a person walking, running, cycling?

A
  1. 1.5 m/s
  2. 3 m/s
  3. 6 m/s
46
Q

Average speed of a bus, train, plane?

A
  1. 25 m/s
  2. 55 m/s
  3. 250 m/s
47
Q

Equation for uniform acceleration?

A

Final velocity^2 - Initial velocity^2 = 2 x acceleration x distance

48
Q

What does the gradient equal on a distance time graph?

A

Speed

49
Q

What does a flat section represent on a distance time graph?

A

Stationary

50
Q

What does a straight uphill section mean on a distance time graph?

A

Constant speed

51
Q

What does a curve represent on a distance time graph?

A

Acceleration/ deceleration

52
Q

What does the gradient represent on a velocity time graph?

A

Constant acceleration/ deceleration

53
Q

What does a flat section away from 0 mean on a velocity time graph?

A

Constant speed

54
Q

What does a curve mean on a velocity time graph?

A

Changing acceleration/ deceleration

55
Q

How to find the distance travelled on a velocity time graph?

A

Area under the graph

56
Q

What forces must balance for constant speed?

A

Driving forces & frictional forces

57
Q

What is drag?

A

Friction or resistance from travelling through a fluid

58
Q

How is drag reduced?

A

Streamlining so fluid can flow easily across it

59
Q

What 2 things can increase drag?

A

.1. Increased speed
2. Large surface area

60
Q

Explain terminal velocity.

A
  1. Weight is greater than air resistance/drag so the object falls quickly
  2. As speed increases, drag increases until the forces are balanced, reaching terminal velocity
61
Q

What is Newton’s first law?

A

If the resultant force on stationary object is zero, it will remain stationary. If the resultant force on a moving object is zero, it will continue moving at constant velocity.

62
Q

What are the 5 different forms of acceleration?

A

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

63
Q

Relationship between acceleration & resultant force?

A

Directly proportional

64
Q

Relationship between mass & acceleration?

A

Inversely proportional

65
Q

What is Newton’s second law?

A

Force = mass x acceleration

66
Q

What is an object’s inertial mass & how is it found?

A

How difficult it is to change the velocity of an object (found using Newton’s second law)

67
Q

What is Newton’s third law?

A

When two objects interact, they produce equal, opposite reactions

68
Q

What are the 2 components of stopping distance?

A

Braking distance + thinking distance

69
Q

2 factors that affect thinking distance?

A
  1. Speed
  2. Reaction time
70
Q

3 conditions that impact braking distance?

A
  1. Speed
  2. Weather conditions
  3. Condition of tyres
71
Q

How does braking work?

A

When brakes are pressed, brake pads are pressed onto the wheels causing friction until the friction equals the driving force and the car stops

72
Q

Why can extreme brakes damage the car?

A

When braking, energy from the kinetic store transfers to the thermal energy store
- If too much energy transfers the brakes could overheat

73
Q

3 factors which can affect reaction time?

A
  1. Drugs
  2. Alcohol
  3. Tiredness
74
Q

Why does thinking distance increase with speed?

A

Thinking distance stays constant, but the faster the car moves, the more ground travelled by the car in a shorter time

75
Q

2 factors which can increase momentum?

A
  1. Big velocity
  2. Big mass
76
Q

Equation for momentum

A

Momentum = mass x velocity

77
Q

What is conservation of momentum?

A

In a closed system, the total momentum before an event will equal the total momentum after

78
Q

What can change momentum?

A

A non-zero resultant force changes an object’s velocity, therefore changing momentum

79
Q

What does F=m x v-u/t mean?

A

Force is equal to the rate of change of momentum

80
Q

What are risks of momentum changing majorly very quickly?

A

Forces on the body will be very large, meaning large impacts

81
Q

3 safety features on cars?

A
  1. Crumple zones to increase time taken for car to stop
  2. Seat belts stretch slightly to increase time taken for passenger to stop
  3. Air in air bags slows you down gradually
82
Q
A

Physics (8 decks)

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