Question

Awanita is placing items on a shelf that is 200 cm above the ground. She exerts a force of 20 N to lift a box from the floor to the shelf. She does this in 5 s.

What is Awanita’s power output? (Power: P = W/t)

4 W
8 W
40 W
800 W

Answer 1

First convert the shelf height to meters: 200 cm = 2.00 m.

Work done W = F × d = 20 N × 2.00 m = 40 J.

Power P = W / t = 40 J / 5 s = 8 W.

Answer: 8 W.