Question

A dog of weight $400N$ climbs up a cliff of height $10m$ in $20seconds$. The power expended by the dog is.

• A. $100W$
• B. $200W$
• C. $400W$

Answer 1

The correct option is B $200W$

Given,
Weight of the dog, $mg=400N$
Displacement or height, $h=10m$
Time taken, $t=20s$

We know, power, $P=\frac{Workdone}{timetaken}$
$=\frac{mgh}{t}$
$=\frac{400\times 10}{20}$
$=\frac{4000}{20}$
$=200W$