Question

A 60-kg woman runs up a staircase 15 m high (vertically) in 20 s.

Answer 1

Answer:

(a) 441 W (b) 0.59 hP

Explanation:

Given that,

Mass of a woman, m = 60 kg

Height of a staircase, h = 15 m

Time, t = 20 s

(a) We need to find the power she expend. Work done per unit time is called power. It is given by :

$P=\dfrac{W}{t}\\\\P=\dfrac{mgh}{t}\\\\P=\dfrac{60\times 9.8\times 15}{20}\\\\P=441\ W$

( b) Since, 1 hP = 745.7 W

P = 0.59 hP