(a)[4]
Calculate the rate at which gravitational potential energy is transferred as the load drops to the ground.
(b)[2]
Calculate the efficiency of the ‘gravity lamp’.
(c)[1]
Suggest one social or environmental advantage of using a ‘gravity lamp’.
Physics 0625 · IGCSE · Energy, work and power
Energy, work and power — practice question
Fig. 2.1 gives a simplified diagram of a ‘gravity lamp’. This device lights a light-emitting diode (LED) without mains electricity. A load of 12 kg is lifted to a height of 1.7 m above the ground and attached to a pulley system. It takes 1200 seconds for the load to reach the ground. The load moves down at constant speed. The generator is linked to an LED.
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