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

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

What is a vector quantity?

A

Direction and magnitude

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

What is a scalar quantity?

A

Magnitude only

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

How are vector quantities usually represented by?

A

An arrow showing direction and length shows magnitude

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

What are some 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
5
Q

What are some 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
6
Q

What are contact forces?

A

Have to be touching for a force to act (e.g. friction, air resistance)

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

What are non-contact forces?

A

Don’t have to be touching for force to act (e.g. gravitational force, electrostatic force)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
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
9
Q

What is mass?

A

The amount of stuff in an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
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
11
Q

What does the weight of an object depend on?

A

The strength of the gravitational field at the location of the object

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

What is the relationship between mass and weight?

A

They are directly proportional

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

What does a free-body diagram show

A

All the forces acting on an isolated object
Size of arrows shows the relative magnitude of the forces
Also shows direction

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

What is the resultant force of an object?

A

Add forces going in the same direction
Subtract ones going in different direction
(along the same line)

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

What happens when a force acts on an object?

A

Work is done to move the object so energy is transferred from one store to another

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

How do you convert joules to newton metres?

A

1J = 1Nm

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

How do you calculate resultant forces using scale drawings?

A

Draw forces (North however many cm then East)
Calculate the line (triangle) between them starting from where the force started

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

What happens when all the forces acting on an object equal 0?

A

The object is in equilibrium

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

How do you find the single force of a force acting at an awkward angle?

A

Draw the components at right angles to each other
Horizontal and vertical component then work out line connecting them

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

What can an object do if it has been elastically deformed?

A

It 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
21
Q

What happens when work is done and an object is stretched or compressed (force wise)?

A

Energy is transferred to the elastic potential energy store

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

What forces need to be applied for an object to stretch, compress or bend?

A

More than one force acting on the object or otherwise it would just move in the direction the force is pushing/pulling

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

What is the relationship between extension and force applied/load?

A

They are directly proportional

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

What does the spring constant of a spring depend on?

A

The stiffer the material the greater the spring constant

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

What is the limit of proportionality of a spring?

A

When the force is great enough (limit to amount) that it is not directly proportional to the extension anymore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
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
27
Q

What can increase moment?

A

A larger force or a longer distance

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

What will happen if the total anticlockwise moment is equal to the total clockwise moment?

A

The object is balanced and won’t turn

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

What do levers do?

A

They increase the distance from the pivot at which the force is applied so less force is needed to get the same moment

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

What are gears?

A

Circular discs with teeth around the edges which interlock so that turning one causes another to turn

31
Q

What are gears used for?

A

Transmit the rotational effect of a force from one place to another

32
Q

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

A

The bigger the gear the bigger the moment as the distance from the pivot is greater

33
Q

How do particles in fluids exert pressure?

A

Particles in fluids can flow and move around
They collide with surfaces and other particles
Particles are light but still have a mass and exert a force so they exert a pressure

34
Q

What is the density of an object?

A

A measure of the compactness of a substance
How close together the particles in a substance are

35
Q

How does density affect the pressure in a liquid?

A

The more dense a liquid is the more particles there are in certain space
This means more particles can collide so the pressure is higher

36
Q

What happens to the pressure of a liquid as the depth increases?

A

The number of particles above that point increases
The weight of these particles adds to the pressure felt at that point
So liquid pressure increases

37
Q

What happens to an object when they are in a fluid?

A

The pressure of the fluid exerts a force on it from all directions
Pressure increases with depth so the pressure on the bottom of the object is larger than on top
This causes a resultant force called up thrust

38
Q

What is up thrust equal to?

A

Up thrust = weight of the fluid that has been displaced

39
Q

What happens if the up thrust is equal to the weight of the object in a fluid?

A

The object will float

40
Q

What happens if an objects weight is more than the up thrust in a fluid?

A

The object will sink

41
Q

What happens if the object (in a fluid) is denser than the amount fluid it displaces?

A

It will sink

42
Q

What happens to the atmospheric pressure as the altitude increases?

A

Atmospheric pressure decreases

43
Q

Why does the atmospheric pressure decrease as altitude increases?

A

Because as altitude increases the atmosphere gets less dense so there are fewer air molecules that are able to collide with the surface
Also fewer air molecules above a surface so the weight of the air above is less

44
Q

What is displacement?

A

A vector quantity
Distance with direction

45
Q

If you walk 5m north and 5m south, what is your displacement?

A

0m

46
Q

What does it mean when an object is travelling at a constant speed with a changing velocity?

A

The object is changing direction whilst staying at the same speed

47
Q

What is the speed of a person walking?

A

1.5 m/s

48
Q

What is the speed of a person running?

A

3 m/s

49
Q

What is the speed of a person cycling?

A

6 m/s

50
Q

What is the speed of a car?

A

25 m/s

51
Q

What is the speed of a train?

A

30 m/s

52
Q

What is the speed of a plane?

A

250 m/s

53
Q

What is acceleration?

A

The change in velocity in a certain amount of time

54
Q

What is the gradient on a velocity time graph?

A

Accleration

55
Q

What is a flat section on a velocity time graph?

A

Constant speed

56
Q

What is the area under a graph show for velocity time graphs?

A

The total distance travelled

57
Q

What forces have to be balanced for an object to travel at a constant speed?

A

Frictional force and driving force

58
Q

What is drag?

A

The resistance you get in a fluid (liquid or gas)

59
Q

What does it mean if an object is streamlined?

A

It is designed so that fluid can flow easily across it therefore reducing the drag

60
Q

What happens to an object when it falls?

A

The force of gravity is greater than the frictional forces so it accelerates
As speed increases friction builds up
The acceleration gradually decreases until the frictional force is equal to the accelerating force
This is its terminal velocity

61
Q

What is Newton’s first law?

A

If the resultant force on a stationary object is 0 then it will remain stationary
If the resultant force on a moving object is 0 it’ll carrying on moving at the same velocity

62
Q

What is the relationship between acceleration and mass?

A

They are inversely proportional

63
Q

What will a non-zero resultant force produce?

A

Acceleration

64
Q

What is Newton’s second law?

A

If a force acts on an object it will cause it to accelerate

65
Q

What is Newton’s third law?

A

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

66
Q

What is inertia?

A

The tendency to continue in the same state of motion

67
Q

What is an objects inertial mass?

A

How difficult it is to change the velocity of the object

68
Q

What can affect your thinking distance when braking?

A

Speed
Reaction time

69
Q

What can affect your braking distance when braking?

A

Speed
Weather/road surface
Condition of tyres
How good your brakes are

70
Q

What happens when you brake?

A

Brake pedal is pushed
Brake pads are pressed onto the wheels which causes friction which causes work to be done
Energy is transferred from the kinetic energy stores of the wheels to the thermal energy stores of the brakes (increases temp

71
Q

How does speed affect braking?

A

The faster a vehicle is going, the more energy it has in its kinetic store, so more work has to be done to stop it

72
Q

What factors affect momentum?

A

Increased velocity or mass means increased momentum

73
Q

What is the momentum in a closed system?

A

Total momentum before = total momentum after (conservation of momentum)

PHYSICS (12 decks)

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