Paper 5 of 5 · Topics 1–5

Home and garden

Pearson Edexcel International GCSE

Physics — Year 10 Paper 5

Home and garden · mixed Topics 1–5

Time allowed: 40 minutes

Total marks: 25

Candidate name:

Centre / class:

Answer all questions. You may use a calculator. Take $g = 10\,\text{N/kg}$. Show your working. This paper samples Topics 1–5 (Double Award only).

1

Topic 1 A skydiver falls from a plane and reaches terminal velocity before opening the parachute.

(a) Name the two forces acting on the skydiver in the vertical direction while falling.

[2]

(b) Explain, in terms of forces, why the skydiver reaches a terminal velocity.

[3]

(Total for Question 1 = 5 marks)

2

Topic 2 A lamp is connected in series with an LDR and a $6.0\,\text{V}$ battery.

(a) State what happens to the resistance of the LDR when it is covered, and what happens to the current in the lamp.

[3]

(b) A thermistor is used in a similar circuit to switch a fan on when a room warms up. State what happens to the resistance of a thermistor as temperature increases.

[2]

(Total for Question 2 = 5 marks)

3

Topic 3 Optical fibres use total internal reflection to carry pulses of light.

(a) Draw, or describe, the path of a ray that stays inside a straight optical fibre by TIR.

[2]

(b) Ultraviolet is used in some sterilising lamps. State one useful application and one hazard of ultraviolet radiation.

[3]

(Total for Question 3 = 5 marks)

4

Topic 4 A room heater warms air, which then circulates around the room.

(a) Explain how a convection current is set up in the air.

[3]

(b) The heater has an input energy of $2000\,\text{J}$ in a given time. $1600\,\text{J}$ is usefully transferred thermally to the room. Calculate the efficiency.

[2]

(Total for Question 4 = 5 marks)

5

Topic 5 A gardener of weight $800\,\text{N}$ stands on soft soil. Each boot has area $0.020\,\text{m}^2$ in contact with the ground.

(a) Calculate the pressure on the soil when the gardener stands on both feet.

[3]

(b) The gardener then stands on a wide board. Explain why this reduces the pressure on the soil.

[2]

(Total for Question 5 = 5 marks)

END OF PAPER 5 — Home and garden