A 60‑kg woman runs up a flight of stairs having a rise of 4.0 m in a time of 4.2 s. What average power did she supply?

56 W

Explanation:

Power: This can be defined as the rate at which work is done. The S. I unit of power is Watt (W). The Formula of power is given as,

P = W/t

or

P = mgh/t ... Equation 1

Where P = power, m = mass of the woman, g = acceleration due to gravity, h = height, t = time.

Given: m = 60 kg, g = 9.8 m/s², h = 4.0 m, t = 4.2 s.

Substitute into equation 1

P = 60 (4) (9.8) / 4.2

P = 235.2/4.2

P = 56 W.

Hence the average power supplied by the woman = 56 W