Brainscape's Knowledge GenomeTM

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


See full index

A-level Physics Edexcel > Topic 2 : Mechanics > Flashcards

Topic 2 : Mechanics Flashcards

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

Define speed.

A

Speed is defined as the rate of change of distance.

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

Define instantaneous speed.

A

Instantaneous speed is the speed of an object over a very short time interval.

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

How can instantaneous speed me determined?

A

It can be determined by analyzing the gradient of a distance-time graph at a given time.

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

Define displacement.

A

The displacement of an object is the distance it has travelled in a given direction, so it is a
vector quantity, with both magnitude and direction.

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

Define velocity.

A

The velocity of an object is defined as the

rate of change of displacement

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

Define acceleration.

A

Acceleration is defined as the rate of change of velocity

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

There are four equations of motion that can be used for an object travelling with constant acceleration. state the collective name for those equations.

A

SUVAT equations

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

State the method you would use to investigate terminal velocity and momentum of a given object.

A

The terminal velocity of a falling object can be determined using light gates connected to a timer or data logger. The time when each of two light beams are broken by the object is recorded, and these times, combined with the known distance between the light-gates, can be used to calculate the velocity of the object. This technique can also be used to investigate the conservation of momentum resulting from a collision, with the objects suspended on a linear air track, to minimise energy lost to overcoming friction and keep the collision as elastic as possible. A small strip of cardboard can be attached to the object to interrupt the light beam.

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

Describe how you would investigate the g.

A

There are several methods that can be used to determine g. A commonly used method involves a
trapdoor and an electromagnet. An electromagnet holds a small steel ball, suspended a known
distance over the trapdoor. At the instant the electromagnet is deactivated a timer begins, and
stops only at the instant the trapdoor is hit. As the ball was initially at rest, it’s initial velocity is
0, and the distance it has fallen and the time this has taken are known, so these values can be
substituted in to the equation s = ut + ½ at2
, which is rearranged to find a (as there are no other
forces acting on the ball, it’s acceleration is equal to g)
Another method to find the acceleration of free fall involves filming the fall of a small metal
ball against a ruler. If the number of frames per second is known, then the time taken for the
ball to move from rest a known distance down the ruler can be calculated, and used to find g.

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

What is a projectile?

A

A projectile is an object that is thrown at an angle to the horizontal, and therefore moves in
both the horizontal and vertical planes

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

What do you assume when carrying out calculations concerning projectile motion?

A

we assume that there is no air resistance.

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

Define stopping distance of a car.

A

The stopping distance of a car is defined as the total distance travelled from when the driver of
the car sees a hazard requiring them to stop, to the point they actually stop. It consists of two
components, the thinking distance and the braking distance.

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

Define thinking distance.

A

Thinking distance is the distance travelled between the moment the hazard is spotted, and the
moment the driver applies the brake

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

define breaking distance.

A

The braking distance is the distance travelled from the time

the brake is applied to the time the vehicle comes to a complete stop.

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

What is thinking distance proportional to?

A

The thinking distance is proportionate to the initial speed, u, of the car

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

How can you calculate thinking distance?

A

The thinking distance

can be calculated by multiplying the initial speed of the car by the reaction time of the driver.

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

What is thinking distance affected by?

A

The thinking distance is affected by the initial speed of the car, and factors that affect the
driver’s reaction time, such as tiredness, being under the influence of alcohol or drugs, and
other distractions.

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

What is breaking distance proportional to?

A

The braking distance of the car is proportionate to the square of the initial speed of the car, u2 . This is because in order for the car to stop, all of its kinetic energy must be dissipated by the
brakes, and kinetic energy = ½ mv2.

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

What factors affect breaking distance?

A

As well as the initial speed of the car, the braking distance is
also increased by poor road conditions (e.g icy, wet), and the car conditions (e.g bald tyres,
poor brakes, heavy load).

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

state the SI units for force.

A

kgms-2

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

Define weight.

A

The gravitational force acting on an object, through its centre of mass.

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

Define friction.

A

the force that arises when two surfaces rub against each other.

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

Define drag.

A

the resistive force on an object travelling through a fluid (e.g. water or air).

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

Define tension.

A

the force within a stretched cable or rope.

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

Define up-thrust.

A

the upward buoyancy force acting on an object when it is in a fluid.

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

Define normal contact Force.

A

the force arising when an object rests against another object
acting at a 90° angle to the plane of contact.

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

what is a free body diagram and what are they used for?

A

Free body diagrams can be used to model all of the forces that are acting on an object. Each
force is represented as a vector arrow, scaled to the magnitude of the force they represent, and
pointing in the direction that the force acts. Each arrow should be labelled with the name of the
force it represents.

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

What happens to an object the experineces constant resultant force?

A

If an object experiences a constant net force, then there must be a resultant acceleration,
determined using F = ma.

29
Q

What is a moment of a force?

A

The moment of a force can be defined as the magnitude of the force, multiplied by the
perpendicular distance from the force to the pivot, M=Fx It is the turning effect of the force about an axis or pivot, is measured in Nm. The SI unit is kgm2s-2.

30
Q

What is the distance used to calculate the moment of a force?

A

The distance to be used is the perpendicular distance between the pivot point and the line of
action of the force.

31
Q

Define and explain a couple.

A

A couple is a pair of forces, that have equal magnitude and opposite direction, which are
applied to a body in parallel with each other and along different lines. They act on the body in
order to produce a rotational force about the central pivot point. There is no translational
movement.

32
Q

Define and explain a torque.

A

The torque of a couple is defined as the product of the magnitude of one of the forces, and the
perpendicular separation between the forces. This is equal to the total moment of the couple, as
each force has a moment of its magnitude multiplied by the perpendicular distance between it
and the central pivot, which is half of the total distance between the two forces.

33
Q

Explain the effects of a body being in equilibrium.

A

When a body is in equilibrium, the net force acting on it is 0, and its net moment is also 0.
For a body in equilibrium, the sum of the clockwise moments about any point is equal to the sum of the anticlockwise moments about the same point.

34
Q

Define work done.

A

The work done by a force is defined as the
product of the magnitude of the force and the distance moved by the object in the direction of the
force. If the force used is at an angle to the direction of movement of the object, then the
component of the force parallel to this direction is used.

35
Q

State the units for work done.

A

Nm,

SI base unit is kgm2s-2.

36
Q

Define energy.

A

Energy is the capacity for doing work.

37
Q

Define kinetic energy

A

the energy associated with the motion of an object with mass.

38
Q

Define gravitational potential energy

A

the energy stored by an object at a point in a gravitational field. / Gravitational potential energy is an object’s capacity to do work as a result of its position in a gravitational field, such as the gravitational field of the Earth.

39
Q

Define elastic potential energy

A

the energy stored as a result of a reversible change in an object’s shape.

40
Q

Define electric potential energy

A

the energy of charges due to their position in an electric field.

41
Q

Define sound energy

A

the energy of a mechanical wave due to the movement of atoms.

42
Q

Define internal energy

A

the sum of the randomly distributed kinetic and potential energies of the molecules in a substance.

43
Q

Define electromagnetic energy

A

the energy from electromagnetic waves, stored within oscillating fields.

44
Q

Define nuclear energy

A

the energy stored in nuclei, released when particles in nuclei rearrange

45
Q

Define chemical energy

A

the energy contained in chemical bonds, released when atoms rearrange.

46
Q

State the principles of conservation of energy.

A

The principle of conservation of energy
stated that in a closed system, energy cannot be created or destroyed, but only transferred from
one form to another.

47
Q

Define Power.

A

Power is a measure of the rate of which energy is transferred.

48
Q

State the SI units for power.

A

The SI base unit for power is kgm2s-3.

49
Q

What is efficiency?

A

Efficiency is a measure of how much energy is conserved as useful energy. A greater efficiency
means less energy is wasted.

50
Q

State Newton’s first law.

A

Newton’s first law: An object will remain at rest or continue to travel with constant velocity
unless acted upon by a resultant force.

51
Q

State Newton’s third law.

A

Newton’s third law: When two objects interact, they exert equal and opposite forces on each
other. These forces are always of the same type, and have the same magnitude but they act on
different objects, and in opposite directions.

52
Q

State the 4 fundamental forces.

A

The four fundamental forces are the gravitational, electromagnetic, strong nuclear, and weak nuclear forces.

53
Q

State Newton’s second law.

A

Newton’s second law: The net force acting on an object is directly proportional to the rate of
change of momentum, and is acting in the same direction. In SI units, the constant k of
proportionality is taken as equal to 1.

54
Q

Define linear momentum.

A

The linear momentum, p, of an object is defined as the product of the object’s mass, m, and its
velocity v: 𝑝 =𝑚v.

55
Q

Define impulse.

A

It is a measure of change in momentum

56
Q

What is transfered between objects that collide?

A

When two or more objects collide, there is a transfer of both momentum and kinetic energy.

57
Q

State the principle of momentum.

A

The principle of conservation of momentum states that for a system of interacting objects, the total
momentum in a specified direction remains constant, as long as no external forces act on the
system

58
Q

What happens to KE in an elastic collision?

A

In a perfectly elastic collision, the total kinetic energy of the system will also remain constant.

59
Q

What happens to KE during inelastic collision?

A

in an inelastic collision, some of the kinetic energy will be lost to other forms, such as heat and sound energy. The total energy and the momentum are conserved for both collision
types.

60
Q

In projectile motion, why is acceleration zero?

A

Horizontal velocity always has the same magnitude because there is no force in the horizontal direction and therefore no acceleration.

61
Q

In projectile motion, why is acceleration equal to 9.81m/s^2?

A

Vertical velocity gets bigger and bigger as it goes on by 9.81 m/s

62
Q

What happens to a projectile the longer it travels through air?

A

There would be a greater displacement of the object in the vertical direction.

63
Q

What is the final velocity in the horizontal direction right before a projectile hits the ground?

A

The velocity would be equal to the initial velocity as the projectile has zero acceleration in the horizontal direction.

64
Q

Consider an irregular shaped cardboard in a non-uniform gravitational field. Describe what you would be investigating by drawing plumb lines and how would you carry out the investigation.

A

By hanging the cardboard and use plumb lines to draw vertical lines would be repeated for other points on the cardboard. the point of intersection is the line of the centre of gravity.
Since there’s no uniform gravitational field, the centre of mass and the centre of gravity are not at the same place.

65
Q

Compare the definitions of centre of mass and centre of gravity of an irregular object.

A

The centre of mass is the point through which any externally applied force produces a straight line motion, but no rotation.
The centre of gravity is an imaginery point where the entire wight of an object appears to act.

66
Q

When can the centre of mass and centre of gravity of an object be found in the same place?

A

When the object is placed in a uniform magnetic field.

67
Q

State the variables that the centre of mass of an object depends on.

A

Size, shape and density.

68
Q

State the variables that the centre of gravity of an object depends on.

A

Size, shape, density and gravitational fields the object is in.

A-level Physics Edexcel (12 decks)

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