Identify the incorrect definition of power.

Four different electric bicycles are driven along a road. The work done by their motor, and the time taken to do that work is shown in the table below. Which of the electric bicycles produces the most power?

A crane lifts four pallets of bricks, each of pallets which weigh 5000 N. The crane lifts each pallet a height of 30m. The crane takes 4 minutes to do this. How much useful power did the crane produce to lift the bricks?

Three boxes each weigh 100 N. A man lifts all the boxes together from the ground on to a shelf that is 1.5m above the ground. The man takes 2.0s to do this. How much useful power does the man produce to lift the boxes?

A car of 1000 kg of mass moved from rest to 108 km/h. if time taken is 10 s, the power of cars engine is ....

The diagram shows an LED light bulb. Which expression gives the efficiency of the bulb?

Which of the following energy transfers is most efficient?

The diagram shows the energy used by a modern lamp. The efficiency of the lamp is ....

An electric motor has an efficiency of 35%. It lifts a 7.2 kg load through a height of 5 m in 3 s. Calculate the input power of the motor. take gravitational acceleration 9.8 m/s²

Look at the diagram of the Sankey diagrams for three different lights (traditional filament lamp, LED, CFL). Which lamp has the highest efficiency?