Question

A 33 kg woman climbs up a flight of stairs so she is now 20 meters above the lowest floor. She does this in 25 seconds. How much power does she use?

Answer 1

By the definition of the power, we have:

$$P=\dfrac{W}{t}=\dfrac{mgh}{t},$$ $$P=\dfrac{33\ kg\cdot9.8\ \dfrac{m}{s^2}\cdot20\ m}{25\ s}=258.72\ W.$$