Question

A boy of mass $50kg$ runs up to a stair case of $45$ steps in $9s$. If the height of a $15cm$, find his power. $(g=10{m/s}^2)$

Answer 1

Given that,

Mass of boy, $m=50kg$

Potential energy at a height of 45 steps , $P=mgh=50\times 10\times 45\times 0.15=3375J$

Time taken to climb $45$ steps , $t=9secs$

Power of boy $=\frac{P}{t}=\frac{3375}{9}=375W$