Brainscape's Knowledge GenomeTM

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


See full index

physics past paper questions > Mechanics, Materials and Waves > Flashcards

Mechanics, Materials and Waves Flashcards

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

State the principle of moments (2 marks)

A
  • Sum of the clockwise moments = sum of the anticlockwise moments
  • For a system in equilibrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Galileo used an inclined plane to investigate the
motion of falling objects.
Explain why using an inclined plane rather than free fall would produce data which is valid when investigating the motion of a falling object. ( 2 marks)

A
  • Freefall is too quick

- Galileo had no accurate method to time freefall

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

Define amplitude of a wave (1 mark)

A
  • Maximum displacement of a wave from equilibrium position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Other than EM radiation, give one example of a transverse wave (1 mark)

A
  • Surface of water

- secondary (S) waves

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

State one application, other than in education, of a polarising filter and give a reason for its use (2 marks)

A
  • Polaroid sunglasses

- To reduce glare

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

With reference to the spring, explain what is meant by limit of proportionality (1 mark)

A
  • The point beyond which force is no longer proportional to extension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

State and explain what happens to the value of angle θ for the first order beam if the wavelength of the monochromatic light decreases. (2 marks)

A
  • angle θ gets smaller

- because path difference gets smaller/d constant, (λ smaller) so sin θ smaller

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

State the difference between a scalar quantity and a vector quantity. (1 mark)

A
  • vector has direction but scalar does not
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

State two vector quantities and two scalar quantities (3 marks)

A
  • Vectors: displacement, velocity, acceleration, force, weight
  • Scalars: speed, mass, energy, time, power
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

State Hooke’s law (2 marks)

A
  • the force needed to stretch a spring is directly proportional to the extension of the spring
  • up to the limit of proportionally
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A student is asked to measure the mass of a rock sample using a steel spring, standard masses and a metre rule. She measured the unstretched length of the spring and then set up the arrangement shown in Figure 2.
Describe how you would use this arrangement to measure the mass of the rock sample. State the measurements you would make and explain how you would use the measurements to find the mass of the rock sample. (6 marks)

A

Measurements
- (use a metre rule to) measure the length of the spring - when it supports a standard mass (or known) mass (m) and when it supports the rock sample
- repeat for different (standard) masses
- accuracy - use a set square or other suitable method to measure the position of the lower end of the spring against the (vertical) mm rule
Use of measurements
- plot graph of mass against length (or extension)
- read off mass corresponding to length (or extension) due to the sample

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

A stationary wave is formed on a steel string fixed at P and Q when it is plucked at its centre.
Explain why a stationary wave is formed on the string. (3 marks)

A
  • progressive waves travel from the centre to the ends and reflect
  • two waves travelling in opposite directions meet
  • superposition
  • waves have the same frequency and wavelength
  • waves have the same amplitude
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

A narrow beam of monochromatic red light is directed at a double slit arrangement. Parallel red and dark fringes are seen on the screen.
Explain the formation of the fringes seen on the screen (4 marks)

A
  • interference fringes formed
  • where light from the two slits overlaps
  • bright (or red) fringes are formed where light (from the two slits) reinforces/ interfere constructively
  • dark fringes are formed where light (from the two slits) cancels/ interferes destructively
  • the light from the two slits is coherent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe how the appearance of the fringes would differ if white light had been used instead of red light for a double slit experiment. (3 marks)

A
  • central (bright) fringe would be white
  • side fringes are (continuous) spectra
  • bright fringes would be blue on the side nearest the centre
  • bright fringes are wider
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The work done by the cyclist when pedalling downhill is 2400 J. Account for the difference between the loss of gravitational potential energy and the gain of kinetic energy of the cyclist and the cycle. (3 marks)

A
  • gain of kinetic energy is greater than the loss of potential energy
  • the cyclist does work
  • KE = GPE +W - energy ‘loss’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe and explain one feature of the crane that prevents it from toppling over when it is lifting a container. (2 marks)

A
  • the counterweight
  • provides a (sufficiently large) anticlockwise moment (about Q) ( to that of the container to prevent the crane toppling clockwise)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

A student investigated how the extension of a rubber cord varied with the force used to extend it. She measured the extension for successive increases of the force and then for successive decreases.
Describe the procedure and the measurements you would make to carry out this investigation. (6 marks)

A
  • diagram showing rubber cord fixed at one end supporting a weight at the other end or pulled by a force
  • means of applying variable force drawn or described (eg use of standard masses)
  • means of measuring cord drawn or described
  • measured force applied ( or known weights used)
  • cord extension measured or calculated
  • repeat for increasing then decreasing length (or force/weight)
  • extension calculated from cord length - initial length
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain why optical fibres used for communications need to have cladding (2 marks)

A
  • keeps signal secure
  • reduces pulse broadening
  • keeps light rays in the fibre
  • prevents scratching of the core
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain why, in practice the ball will not travel as dar before hitting the ground (2 marks)

A
  • air resistance

- causes horizontal deceleration

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

Define the moment of a force about a point (2 marks)

A
  • force x perpendicular distance

- between line of action of force and the point

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

State and explain one reason why the core of the optical fibre is made as narrow as possible. (2 marks)

A
  • To reduce multipath dispersion

- which would cause light travelling at different angles to arrive at different times/ pulse broadening

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

State one application of optical fibres and how it has benefitted society (2 marks)

A
  • endoscope

- improved medical diagnosis

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

What did Young’s double slit experiment suggest about the nature of light (1 mark)

A
  • shows light as a wave rather than a particle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

State what is meant by monochromatic (1 mark)

A
  • single wavelength / frequency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

State what is meant by coherent (1 mark)

A
  • has constant phase difference
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

State one safety precaution while using a laser (1 mark)

A
  • do not look into the laser
  • eyewear
  • signpost clearly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The laser is replaced by another laser emitting visible light with a shorter wavelength in a double slit experiment
State and explain how this will affect the spacing of the maxima on the screen. (2 marks)

A
  • maxima closer together

- spacing is proportional to wavelength (as D and s constant)

28
Q

State one advantage and one disadvantage of wind power in comparison to fossil fuel. (2 marks)

A
  • Advantage: doesn’t emit Carbon dioxide

- Disadvantage: wind is unreliable/ intermittent

29
Q

State which feature of a displacement-time graph represents the velocity. (1 mark)

A
  • Gradient
30
Q

Figure 2 shows the ball deforming as it contacts the ground, just at the point where it is stationary for an instant and has reached maximum deformation.
Explain how Newton’s third law of motion applies to Figure 2. (2 marks)

A
  • ball exerts force on ground and ground exerts force on ball
  • and these forces are equal and opposite
31
Q

Explain why there is a resultant upwards force on the ball in figure 2 (2 marks)

A
  • downwards force is the weight of the ball

- the upward force is greater than the downward force on the ball

32
Q

The student doubles the mass of the card and finds a value for g that is similar to the original value. Use the relationship between weight, mass and g to explain this result. (1 mark)

A
  • W = mg (= ma) and weight is proportional to mass
33
Q

State and explain one reason why the card would give more reliable results than a table tennis ball for this experiment. (2 marks)

A
  • balls acceleration will decrease

- Air resistance affects the cards less

34
Q

Define the moment of a couple (2 marks)

A
  • force × perpendicular distance between the lines of actions of the forces
35
Q

Figure 7 shows a pulse of monochromatic light (labelled X) that is transmitted a significant distance along the fibre. The shape of the pulse after travelling along the fibre is labelled Y. Explain why the pulse at Y has a lower amplitude and is longer than it is at X. (2 marks)

A
  • reduced amplitude due to absorption

- pulse broadening caused by multi-path dispersion

36
Q

A scientist is going to use a double-slit arrangement to carry out measurements in order to determine the wavelength of light from a laser.
The scientist has a double slit of known separation. Describe the measurements that need to be taken and explain how they are used to find the wavelength of the light. Discuss any necessary safety precautions and how you would arrange the apparatus to
improve accuracy. (6 marks)

A 
Measurements
- suitable measuring instrument for w
- suitable measuring instrument for D
Finding the wavelength
- uses λ = ws/D to obtain value for λ
Accuracy
- several fringe spaces measured
- centres of fringes used
- five or more fringes/four fringe spaces measured
- large value of D
- D greater than or equal to 2 m
- dark room
- repeat measurements
- vernier calliper for w 
- graphical method varying D and measuring w
- other valid accuracy point
Safety
- avoid shining laser at (or near) a person
- laser safety goggles
- avoid reflections
- warning sign or light
37
Q

State two differences in the appearance of the pattern obtained with a laser and that produced by a white light source such as a candle in a double slit experiment (2 marks)

A
  • contains different colours

- less intense

38
Q

Explain how the wave theory of light accounts for the areas on the screen where the intensity is a minimum. (2 marks)

A
  • destructive interference

- when light meets in antiphase

39
Q

Equation linking force, power and velocity

A

Force = power/velocity

40
Q

Explain how and why the maximum range of the wheelchair on level ground is affected by:
- the mass of the user
- the speed at which the wheelchair travels
(4 marks)

A 
Increasing mass:
- reduces the range
- increases the friction on the tyres
Increasing speed
- reduces the range
- air resistance increases with speed
41
Q

Explain why the signal strength falls to a minimum between B and C, and between C and D (double slit experiment with microwave transmitter and receiver) (3 marks)

A
  • path difference for two waves
  • gives rise to a phase difference
  • destructive interference occurs
42
Q

The intensity of the waves passing through each slit is the same (double slit experiment). Explain why the minimum intensity between C and D is not zero. (2 marks)

A
  • Intensity decreases with distance
  • One wave travels further than the other
  • Amplitudes/intensities of the waves at the minimum points are not equal
43
Q

State and explain the effect on the signal strength as an aerial is rotated slowly through 90 degrees (3 marks)

A
  • The signal decreases
  • the waves transmitted are polarised
  • zero signal when detector at 90 degrees to the transmitting aerial
44
Q

When wind blows, stationary waves can be formed on the aerial wire. Explain how stationary waves are produced and why only waves of specific frequencies can form on the aerial wire. (4 marks)

A
  • Wind produces a wave that travels along the wire
  • Wave is reflected at each end / waves travel in opposite directions
  • Waves interfere/superpose
  • Only certain frequencies since fixed ends have to be nodes
45
Q

High winds produce large amplitudes of vibration of the aerial wire. Explain why the copper wire may sag when the high wind stops (2 marks)

A
  • Copper may stretch beyond elastic limit

- Permanent deformation

46
Q

Figure 1 shows a truck moving freely down a ramp inclined at an angle to the
horizontal. Figure 2 shows the truck moving down a ramp with a varying slope.The truck starts from rest and moves freely down the ramp. It reaches point C and then moves along the horizontal runway to D. Friction and air resistance are negligible.
Discuss how the acceleration of the truck in Figure 2 differs from the acceleration of
the truck in Figure 1. (3 marks)

A
  • acceleration of truck in Fig.1 is constant
  • In Fig.2 acceleration is greater/greatest at start/top
  • acceleration decreases
  • reference to zero acceleration/uniform velocity between C and D
  • because the component of weight/acceleration parallel to the slope
    changes
47
Q

The total vertical displacement of the centre of mass of the truck in Figure 2 is also 8.0 m
The speed of the truck when it reaches the horizontal runway is the same as the
speed of the truck in Figure 1 when it reaches point A.
Explain why (1 mark)

A
  • the loss of (gravitational) potential energy is the same hence gain in kinetic energy is the same
48
Q

The horizontal runway in Figure 2 has negligible friction and air resistance. As the truck moves along the runway, it starts to rain. The rain falls vertically and water collects in the truck.
Discuss whether there are any changes in the momentum of the truck and collected
water. (3 marks)

A
  • rain has no (initial) horizontal momentum
  • vertical momentum of rainwater decreases
  • no external forces acting on the system
  • mass of truck increases but velocity decreases
  • horizontal momentum of water increases but horizontal momentum of truck decreases
  • no change in total momentum
49
Q

State what is meant by centre of mass (1 mark)

A
  • the point through which a force has no turning effect
    Or
  • where the mass of the body can be considered to be concentrated
50
Q

State two necessary conditions for an object to be in equilibrium (2 marks)

A
  • resultant force = 0

- zero resultant moment

51
Q

Explain why the centre of mass must be vertically below the pivot for a suspended object (2 marks)

A
  • so there is no result moment

- about A because A is the pivot

52
Q

Figure 8 shows a diagram of apparatus used to demonstrate the formation of
interference fringes using a white light source in a darkened room. Light from the
source passes through a single slit and then through two narrow slits S1 and S2. Describe the interference pattern that is seen on the white screen (2 marks)

A
  • central white fringe
  • fringes either side showing spectrum of colours
  • with red furthest and violet closest to the centre
53
Q

A filter transmits only green light of wavelength lambda and red light of wavelength 1.2 lambda. This filter is placed between the light source and the single slit.
Describe the interference pattern now seen on the white screen.
Use a calculation to support your answer. (4 marks)

A
  • central fringe is a mixture of red and green light
  • spacing of red fringes is 20% greater than the green fringes
  • 6th green fringe overlaps with 5th red fringe
54
Q

A student decides to use the apparatus shown in Figure 8 (double slit) to determine the
wavelength of red light using a filter that transmits only red light. The student suggests the following changes:
• decrease slit separation s
• decrease D, the distance between the slits and the screen.
The student decides to make each change independently.
Discuss the effects each independent change has on the interference pattern, and whether this change is likely to reduce uncertainty in the determination of the wavelength. (6 marks)

A

The following statements may be present for decreasing slit separation s:
- Fringe separation increases
- Uncertainty in measuring fringe separation will decrease and as this is needed to measure wavelength, uncertainty in wavelength measurement will decrease
The following statements may be present for smaller D:
- Uncertainty in measuring D would increase
- Fringe separation would also decrease
- so uncertainty in measuring fringe separation would increase
- Both are required to find wavelength so uncertainty in finding wavelength would increase

55
Q

Air enters the engine at A and is heated before leaving B at a much higher speed. State what happens to the momentum of the air as it passes through the engine. (1 mark)

A
  • momentum increases
56
Q

Air enters the engine at A and is heated before leaving B at a much higher speed. Explain, using appropriate laws of motion, why the air exerts a force on the engine in the forward direction. (3 marks)

A
  • rate of change of momentum is force so force acts on the air (Newton 2)
  • Air exerts force on engine of equal magnitude
  • but in the opposite direction (Newton 3)
57
Q

When an aircraft lands, its jet engines exert a decelerating force on the aircraft
by making use of deflector plates. These cause the air leaving the engines to be
deflected at an angle to the direction the aircraft is travelling. The speed of the air leaving B is the same as the speed of the deflected air. Explain why the momentum of the air changes. (2 marks)

A
  • momentum is a vector

- there is a change in direction

58
Q

Suggest why in practice the decelerating force provided by the deflector plates
may not remain constant when an aircraft is landing. (2 marks)

A
  • rate of intake of air decreases as plane slows

- therefore there is a smaller rate of change of momentum

59
Q

Suggest how stationary waves are formed in a microwave oven (2 marks)

A
  • waves are reflected

- and superpose with wave travelling in opposite direction

60
Q

The student removes the turntable and places a bar of chocolate on the floor of
the oven. He then switches the oven on for about one minute. When the chocolate is removed the student observes that there are three small patches of melted chocolate with unmelted chocolate between them. Suggest why the chocolate only melts in certain places (2 marks)

A
  • energy is maximum

- at antinodes

61
Q

Explain why most microwave ovens contain a rotating turntable on which the
food is placed during cooking. (1 mark)

A
  • position of antinode/maximum energy continually changes
62
Q

State what is meant by tensile stress (1 mark)

A
  • the force exerted per cross sectional area
63
Q

State what is meant by tensile strain (1 mark)

A
  • extension over original length
64
Q

How can a graph show that a material is brittle (2 marks)

A
  • linear graph
  • little/ no plastic behaviour
  • large stress for only a small amount of strain
65
Q

Properties you want for a material for
- a cable supporting a lift
- a rope or cable attached to a person doing a bungee jump
(6 marks)

A

Lift:
- High breaking stress
- High Young Modulus
- Some plastic behaviour so warns before failing
Bungee:
- large stress for a given strain increasing the time taken to come to rest
- reduces force felt by person
- can store a large amount of energy before breaking
- not too stiff (lower Young modulus)
- behaves elastically so returns to original length

physics past paper questions (1 decks)

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