Physics (AS & A Level) · Feb / March 2019 · Paper 12 · Question 16

A crane is being used to lift containers off a ship. One container has a mass of 14 000 kg and is being lifted vertically with a speed of 3.2 m s–1. The electric motor being used to supply the power to lift the container is using a current of 240 A at a potential difference of 2200 V. What is the efficiency of the system?

1. A8.1%
2. B8.5%
3. C48%
4. D83%

As printed in the paper