Airport workers use an electric conveyor belt to lift cargo suitcases of identical mass into an airplane's hold.
To speed up loading, they increase the speed of the conveyor belt's motor so that more suitcases are lifted up to the hold in a given time.
How does this change affect the work done in lifting each suitcase, and the useful output power of the motor?
Work done: increases; useful output power: decreases
Work done: increases; useful output power: increases
Work done: no change; useful output power: decreases
Work done: no change; useful output power: increases
533 exam-style questions on CIE IGCSE Physics 1.7 Energy, work and power, covering 1.7.1a Energy stores and energy transfers, 1.7.1b Conservation of energy, 1.7.1c Kinetic and gravitational potential energy, 1.7.2 Work done, 1.7.3 Energy resources, 1.7.3a Energy resources and electricity generation, 1.7.3b Nuclear fusion as an energy source, 1.7.3c Efficiency of energy transfer, and 1.7.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.