EnergyAQA GCSE Physics: Topic test

20 questions, 54 marks

AQA GCSE Physics

Energy topic test

Total 54 marks

Name

Class

Date

1
A window cleaner's powered lift raises a 75 kg cleaning platform from ground level to a height of 20 m at a steady speed, taking 25 s. Take gravitational field strength g = 9.8 N/kg.
(a)
As the platform rises, which energy store increases?
[1 mark]
AThe chemical energy store of the platform
BThe gravitational potential energy store of the platform
CThe kinetic energy store of the platform
DThe elastic potential energy store of the platform
(b)
Which equation should be used to calculate the useful work done in raising the platform to height h?
[1 mark]
AW = 1/2 m v^2, where v is the speed of the platform
BW = Q/t, where Q is the charge moved
CW = Fs, where F is the weight of the platform and s is the height risen
DW = 1/2 k e^2, where e is an extension
(c)
Calculate the gravitational potential energy gained by the platform as it is raised to a height of 20 m. Give your answer in joules, including the equation used and your working.
[2 marks]
Total for question 1: 4 marks
2
A tractor pulls a loaded trailer across a level field using a horizontal chain with a tension force of 4500 N. The trailer moves 60 m in 40 s.
(a)
Which equation should be used to calculate the work done by the tractor in pulling the trailer 60 m?
[1 mark]
AW = Fs, where F is the tension force and s is the distance moved
BW = mgh, where h is a vertical height
CW = QV, where Q is the charge moved
DW = 1/2 m v^2, where v is the speed of the trailer
(b)
Which physical quantity is calculated using the equation P = W / t, where W is work done and t is time taken?
[1 mark]
AEfficiency
BKinetic energy
CElectrical charge
DPower
(c)
Calculate the power output of the tractor as it pulls the trailer 60 m in 40 s using the tension force given. Give the equation used, your working, and the final answer with unit.
[2 marks]
Total for question 2: 4 marks
3
A washing machine motor is supplied with 1200 J of electrical energy every second. Of this, 900 J is usefully transferred to the kinetic energy store of the drum and clothes every second, and the rest is wasted to the thermal energy store of the motor casing.
(a)
Calculate the efficiency of the washing machine motor. Give your answer as a decimal and as a percentage.
[3 marks]
(b)
Suggest and explain two different ways that engineers could reduce the amount of energy wasted to the thermal energy store in the washing machine motor.
[4 marks]
Total for question 3: 7 marks
4
A remote off-grid research station in Antarctica currently generates all of its electricity by burning imported diesel fuel, delivered by ship twice a year. The station's main accommodation block has thin, poorly insulated aluminium walls, and staff report the block cools quickly whenever the heating is switched off.
(a)
Engineers are considering supplementing the diesel generators with a mixture of wind turbines and solar panels. Evaluate the advantages and disadvantages of adding wind and solar generation to the station's energy supply, compared with relying solely on diesel.
[6 marks]
(b)
Explain, using the idea of thermal conductivity, why the accommodation block cools quickly, and evaluate two specific measures the engineers could take to reduce its rate of heat loss.
[6 marks]
Total for question 4: 12 marks
5
In a fairground game, a mallet transfers 98 J to the kinetic energy store of a 2 kg puck, launching it vertically upward along a smooth vertical track. Take gravitational field strength g = 9.8 N/kg.
(a)
As the puck rises after being launched, which energy store decreases?
[1 mark]
AThe gravitational potential energy store
BThe chemical energy store
CThe kinetic energy store
DThe elastic potential energy store
(b)
At the puck's maximum height, assuming no energy is transferred to the thermal energy store, which statement is correct?
[1 mark]
AAll of the energy originally transferred to the puck is still in its kinetic energy store
BAll of the energy originally transferred to the puck's kinetic energy store has been transferred to its gravitational potential energy store
CEnergy has been destroyed as the puck rose
DThe elastic potential energy store of the puck is at its maximum
(c)
Assuming no energy is transferred to the thermal energy store, calculate the maximum height risen by the puck.
[2 marks]
Total for question 5: 4 marks
6
An electric drill motor does 3600 J of work in 45 s while driving a screw into a wooden beam, overcoming a constant resistive force of friction along the screw's path.
(a)
Which equation should be used to calculate the power output of the drill motor, given the work done and the time taken?
[1 mark]
AP = Fs
BP = mgh
CP = QV
DP = W/t
(b)
Which equation links the work done by the drill motor to the resistive force overcome and the distance moved?
[1 mark]
AW = Fs, where F is the resistive force and s is the distance moved
BW = 1/2 m v^2, where v is a speed
CW = QV, where Q is the charge moved
DW = 1/2 k e^2, where e is an extension
(c)
Calculate the power output of the drill motor. Give the equation used, your working, and the final answer with unit.
[2 marks]
Total for question 6: 4 marks
7
An old-style incandescent light bulb is supplied with 60 W of electrical power. Of this, only 4.2 W is usefully transferred to the light energy store, and the rest is wasted, mostly to the thermal energy store of the bulb and surroundings.
(a)
Calculate the efficiency of the incandescent bulb. Give your answer as a decimal and as a percentage.
[3 marks]
(b)
A homeowner is deciding whether to replace all the incandescent bulbs in their house with LED bulbs, which have a much higher efficiency. Explain, in terms of energy stores and efficiency, why LED bulbs need less electrical energy than incandescent bulbs to produce the same amount of light, and suggest one other benefit of making the switch.
[4 marks]
Total for question 7: 7 marks
8
A family living in a 1930s semi-detached house with solid brick walls and single-glazed windows notices very high heating bills every winter. They are also considering installing solar photovoltaic (PV) panels on their roof to generate some of their own electricity.
(a)
Explain, using the idea of thermal conductivity, why the house loses heat quickly, and evaluate two specific measures the family could take to reduce the rate of heat loss.
[6 marks]
(b)
Evaluate the advantages and disadvantages of the family installing solar PV panels, compared with continuing to buy all their electricity from the national grid.
[6 marks]
Total for question 8: 12 marks

End of questions