Total marks: 80 · Duration: 75 minutes · Tier: Core
Instructions to candidates
• Answer all questions in both Section A and Section B. • Write your answers in the spaces provided on the question paper. • You may use a calculator. • Take the acceleration of free fall g = 10 m/s² unless otherwise stated. • The number of marks is given in brackets [ ] at the end of each question or part question. • The total mark for this paper is 80. Section A carries 48 marks and Section B carries 32 marks.
Paper
Section A — Structured Questions (48 marks)
1. A student investigates the motion of a trolley on a sloping runway. The runway is 2.0 m long and inclined at 15° to the horizontal. A light gate at the bottom of the runway measures the speed of the trolley.
The trolley is released from rest and travels down the runway. The light gate measures the final speed of the trolley as 2.8 m/s.
(a) State what is meant by the term acceleration. (2 marks)
(b) Calculate the average speed of the trolley as it travels down the runway. (1 mark)
(c) Calculate the time taken for the trolley to travel down the runway. (2 marks)
(d) The student repeats the experiment but increases the angle of the slope.
Suggest how this change affects the time taken for the trolley to reach the bottom of the runway. Explain your answer. (2 marks)
2. A crane lifts a steel girder of mass 450 kg vertically upwards at a constant speed of 0.5 m/s.
(a) Calculate the weight of the girder. (2 marks)
(b) State the size of the upward force provided by the crane cable when the girder is moving at constant speed. (1 mark)
(c) The crane lifts the girder through a vertical height of 12 m.
Calculate:
(i) the work done by the crane (2 marks)
(ii) the power output of the crane. (2 marks)
(d) Explain why the actual power input to the crane motor must be greater than your answer to part (c)(ii). (2 marks)
3. In a simple electric circuit, a 6.0 V battery is connected in series with two resistors, R₁ = 8.0 Ω and R₂ = 4.0 Ω, and an ammeter. A voltmeter is connected across R₁.
(a) Calculate the total resistance of the circuit. (1 mark)
(b) Calculate the current shown on the ammeter. (2 marks)
(c) Calculate the reading on the voltmeter. (2 marks)
(d) The resistor R₁ becomes hot during operation.
Explain, in terms of charge and energy transfer, why R₁ becomes hot. (3 marks)
4. A student investigates the reflection of light using a plane mirror.
(a) A ray of light strikes a plane mirror. The angle of incidence is 35°.
(i) State the angle of reflection. (1 mark)
(ii) Work out the angle between the reflected ray and the surface of the mirror. (1 mark)
(b) Describe an experiment to verify the law of reflection using a ray box, plane mirror, protractor and white paper. Include in your answer:
- the measurements you would take
- how you would use the measurements to verify the law. (4 marks)
(c) Explain why you can see your reflection in a mirror but not in a sheet of white paper. (2 marks)
5. A sample of water is heated from 20°C to 100°C.
(a) State the temperature change in kelvin. (1 mark)
(b) The mass of water is 0.50 kg. The specific heat capacity of water is 4200 J/(kg°C).
Calculate the energy required to heat the water. (3 marks)
(c) As the water is heated, its temperature rises steadily from 20 °C at 0 minutes to 100 °C at 8 minutes. It then stays at 100 °C from 8 minutes to 10 minutes.
(i) Describe what is happening to the water between 8 and 10 minutes. (1 mark)
(ii) Explain, in terms of energy, why the temperature does not increase during this time even though the water continues to be heated. (2 marks)
6. Radioactive decay occurs in the nuclei of unstable atoms.
(a) Complete the table below to show the nature and penetration properties of nuclear radiation.
| Type of radiation | Nature | Stopped by |
|---|---|---|
| alpha (α) | paper | |
| beta (β) | fast-moving electron | |
| gamma (γ) | electromagnetic wave |
(3 marks)
(b) A radioactive source has a half-life of 6 hours and an initial count rate of 800 counts per minute.
(i) State what is meant by half-life. (2 marks)
(ii) Calculate the count rate after 18 hours. (2 marks)
(c) Explain why radioactive sources used in hospitals for medical diagnosis should have short half-lives. (2 marks)
Section B — Extended Response (32 marks)
7. A transport company is deciding between using diesel-powered trucks and electric-powered trucks for deliveries.
Table 7.1 shows information about the two types of truck.
Table 7.1
| Feature | Diesel truck | Electric truck |
|---|---|---|
| Cost to purchase | £45 000 | £72 000 |
| Energy cost per 100 km | £18 (diesel fuel) | £6 (electricity) |
| Carbon dioxide emissions per km | 180 g | 0 g (at point of use) |
| Maximum range on full tank/charge | 800 km | 400 km |
| Refueling/recharging time | 5 minutes | 2 hours |
| Expected lifetime | 15 years | 15 years |
The company's trucks each travel approximately 40 000 km per year.
Using the information provided and your knowledge of physics, evaluate the advantages and disadvantages of each type of truck.
Your answer should include:
- calculations of the total running costs over the lifetime of each truck
- discussion of efficiency and energy transfers
- consideration of environmental impact
- a justified recommendation for which type of truck the company should choose.
(15 marks)
8. Nuclear power stations generate electricity by nuclear fission. Some people support building more nuclear power stations while others oppose them.
(a) Describe the process of nuclear fission in a nuclear reactor. Your answer should include:
- what happens to the nucleus during fission
- what is released during the reaction
- how a chain reaction is maintained. (6 marks)
(b) Discuss the advantages and disadvantages of using nuclear power stations to generate electricity compared to using fossil fuel power stations.
Your answer should consider:
- energy output and efficiency
- environmental impact
- fuel availability
- safety concerns
- waste disposal.
You should reach a justified conclusion about whether more nuclear power stations should be built. (11 marks)