Question

Trevor lifts a 10kg box to the top of a cliff which is 20m high, in half an hour, then drops the box over the cliff. How much power did he use to lift the box?

Answer 1

P=1.11Watts

Step-by-step explanation:

Mass if box: m=10kg

Height: h=20m

g=10m/s²

Duration of action: t=30min=1800s

Work to lift the box:

W=m×g×h=10×10×20=2000J

Power: P=W/t=2000/1800=1.11Watts