Question

A man of mass 80kg climbs up 15 steps each 25cm high in 7.5 seconds. Calculate the power that the man develops ​

Answer 1

Explanation:

Given that ,

A man whose mass is 80kg climbs up 15 steps of a stair in 7.5sec

each step is 25 cm high

Height at 15 steps , h=15×0.25= 3.75.

Change in potential energy ,

=mgh=80×10×3.75= 3000 J

So, Work done by the man , W=3000 J

Power used , P= W/ t

= 3000/ 7.5

= 400 W.