Brainscape's Knowledge GenomeTM

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


See full index

physics > topic 5: forces > Flashcards

topic 5: forces Flashcards

1
Q

6 examples of scaler quantities

A

mass temperature speed energy distance time

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

what is scaler and vector

A

scaler-just magnitude no distance
vector-magnitude and distance

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

name 6 vector quantities

A

displacement weight force velocity acceleration momentum

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

what is a force

A

A force is a push or pull that acts on an object due to the interaction with another object

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

is force vector or scaler

A

vector

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

name contact forces

A

tension,friction,air resistance

normal contact force-(lamp) the lump is exerting a downward force on the table which is the weight 

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

name non contact force

A

gravitational force,electrostatic force,magnetic force

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

what is the weight of an object

A

The weight of an object is the force acting on it due to gravity
newtons

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

what is weight equation

A

weight (N) = mass (kg) x gravitational field strength (N/kg)

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

what is the centre of mass

A

The weight of an object can be considered to act a singular point

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

how can a vector quantity be drawn and what does it show?

A

As an arrow

The length of the arrow represents the magnitude

The arrow points in the associated direction

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

what is a force? 

A

A push or a pole acting on an object due to an interaction with another object

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

give three examples of vector quantities

A

Velocity
Displacement
Force

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

What is weight?

A

The force that act on an object due to gravity and the object mass

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

What is meant by an object centre of mass?

A

The single point where an object weight can be considered to act through

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

what piece of equipment can be used to measure objects weight?

A

A calibrated spring balance or Newton meter

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

what is the name given to the single force that is equivalent to all the other forces acting on a given object

A

The resultant force

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

What does it mean if a force is said to do work?

A

The fast causes an object to be displaced through a distance

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

what distance must be used when calculating work done?

A

It must be the distant that is moved along the line of action of the force

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

What occurs when Work has done against frictional forces

A

A rise in temperature of the object occurs

Kinetic energy is converted to heat

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

Why does air resistance slow down a projectile?

A

The object does work against the air resistance

Kinetic energy is converted into heat, slowing down the object

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

explain the relationship between the far supplied and the extension of an elastic object

A

The extension is directly proportional to the force applied, provided that the limit of proportionality is not exceeded

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

what is meant by an inelastic deformation?

A

A deformation which results in the object being permanently stretched

The object doesn’t return to its original shape when the force is removed

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

What can extension be replaced with in the equation for spring force?

A

Compression

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

what is an alternative name for the turning effect of a force?

A

A moment

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

What distant measurement is used when calculating the moment?

A

The perpendicular distance from the pivot to the line of action of the force

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

If an object is in equilibrium, what can be said about the moment acting on the object?

A

The clockwise moments are equal to the anticlockwise moments

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

what 3 parts make up a lever system?

A

load
effort
pivot

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

How can a lever be used as a force multiplier?

A

If the distance between the effort and the pivot is greater than the distance between the pivot and the load, the force applied on the load is greater than the effort force. This is since the moment on both the effort and load must be the same.

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

give an example of when a lever may be used to multiply a force

A

A wrench, which has a long handle also that the force supplied by the user is multiplied

31
Q

What determines the moment of a gear wheel?

A

The size of the wheel

32
Q

describe the moment and speed of a larger year being driven by a smaller gear

A

The larger wheel will rotate more slowly, but will also produce a larger moment

33
Q

what is meant by the term fluid?

A

A liquid or a gas

34
Q

in any fluid at what angle did the forces due to pressure act on a given surface

A

At right angles

35
Q

what happens to the density of the atmosphere when increasing altitude

A

The atmosphere becomes less dense as altitude increases

36
Q

explain why atmospheric pressure decreases with an increase in height

A

Pressure is created by collisions of air molecules

The quantity of molecules decreases as the height increases

This means atmospheric pressure decreases with an increase of hight

37
Q

What is the earths atmosphere?

A

A thin (relative to the magnitude of the Earth) layer of gas surrounding the Earth

38
Q

how does pressure in fluids increase with depth

A

As the depth increases, the mass of liquid above that depth of so increases. This means that the force due to the mass increases. Since the force has increased whilst the area has remained constant, the pressure will increase.

39
Q

why does pressure in fluids increase with density?

A

 density of fluid increases the number of particles in a given volume increases. Consequently the weight of the fluid is greater. This means that the fast from the fluid above the certain point is larger. Since the force has increased, blood pressure also increases.

40
Q

why are objects in a fluid subject to a upthrust

A

when an object is submerged in a fluid, it has a higher pressure below it then it does above, as there is more weight above it at the bottom than there is the top. This leads to an upwards force called upthrust. You float or sink depending on whether upthrust is more or less than your weight. 

41
Q

what is upthrust always equal to?

A

The weight of the fluid that the object displaces

42
Q

what factors influence whether an object will sink or float?

A

upthrust
weight
density of fluid

43
Q

explain why an object with a density greater than of water can never float

A

upthrust is equal to the weight of the displaced fluid. If the density of the object is high, there would not be enough volume displaced to produce an upthrust larger than objects weight 

44
Q

does a distance quantity require a specific direction i.e. is a scaler or vector quantity

A

No specific direction is required so it is a scaler quantity

45
Q

if an object moves 3 m to the left and then 3 m back to its initial position, what is the object total displacement?

A

The object has zero displacement

Displacement is a vector quantity, so it also involves direction

The object starts and ends at the same point

46
Q

State a typical value for the speed of sound

A

330 m/s

47
Q

What is a typical value for the human walking speed?

A

1.5m/s

48
Q

what is the typical value of human running speed?

A

3 m/s

49
Q

What is the typical value for human cycling speed?

A

6 m/s

50
Q

Why can I object travelling at a constant speed in a circle not have a constant velocity?

A

speed is a scaler quantity

Velocity is a vector quantity which means it can only be constant if the direction is constant

In a circular motion, the direction is continuously changing

51
Q

how can speed be calculated from a distant time graph?

A

The speed is equal to the gradient of the graph

52
Q

what must be done to calculate speed at a given time from a distant time graph for an accelerating object

A

Drawing a tangent to the curve at the required time

Calculating the gradient of the tangent

53
Q

how can the distant travelled by an object to be calculated from a velocity time graph

A

It is equal to the area under the graph

54
Q

What can be said about the resultant force acting on an object when it is falling at terminal velocity?

A

The resultant force is zero

When at terminal velocity the object is moving at a constant speed and so isn’t accelerating

55
Q

State Newton’s first law for a stationary object

A

If the result of force on a stationary object is zero, the object will remain at rest

56
Q

State Newton’s first law for a moving object

A

If the result on force on a moving object is zero, the object will remain at a constant velocity

57
Q

what can be said about the breaking forces and driving forces when a car is travelling at constant velocity?

A

The breaking forces are equal to the driving forces

58
Q

if an object changes direction but remains at constant speed, is there a resultant force?

A

Since there is a change in direction, there is a change in velocity and so there must be a resultant force

59
Q

what is inertia

A

The tendency of an object to continue in its state of rest or uniform motion

60
Q

State Newton second law in words

A

An object acceleration is directly proportional to the resultant force acting on it and inversely proportional to its mass

61
Q

what is inertial mass

A

A measure of how difficult it is to change a given object velocity

The ratio of force over acceleration

62
Q

State Newton’s third law

A

Whenever two objects interact, the fastest that they expert on each other are always equal and opposite

63
Q

what is the stopping distance for a vehicle equal to

A

The sum of thinking distance and breaking distance

64
Q

forgiven breaking distance, if the vehicle speed is increased, what can be said about it stopping distance?

A

The stopping distance is increased with an increase in speed

65
Q

give a typical range of values for human reaction time

A

0.2–0.9 seconds

66
Q

Give free factors which can affect a drivers reaction time

A

tiredness
Drugs
alcohol

67
Q

Give two factors which may affect breaking distance

A

adverse road conditions
Poor tire/brake conditions

68
Q

describe the energy transfers that take place when a car applies its brakes

A

Work is done by the friction force between the brakes and wheel

Kinetic energy of the wheel is converted to heat and is dissipated to the surrounding through the brake discs

69
Q

To stop a car in a given distant, if it’s Lotti is increased, what must happen to the breaking force applied

A

The breaking force must also be increased

70
Q

State to consequences of a vehicle undergoing very large decelerations

A

kinetic energy converted to heat is very high causing brakes to overheat

Loss of control of the vehicle

71
Q

In a close system, what can be said about the momentum before and after collision?

A

The total momentum before is equal to the total momentum afterwards

72
Q

what quantity is equal to the force experience in a collision?

A

The rate of change of momentum

73
Q

if an object change of momentum is fixed, what is the only way to reduce the force that the object experiences?

A

Increase the length of time over which the change of momentum occurs

74
Q

Explain how a seatbelt improves a passenger safety during a collision

A

passengers must deaccelerate from the vehicles velocity at impact to 0, meaning they undergo a fixed change of momentum

The first experience is equal to the rate of change of momentum

Seatbelts increase the time over which the force is applied, reducing the rate of change of momentum and therefore reducing the force experienced

physics (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions