Question

A man of mass 50 kg climbs up a ladder of height 10 m. Calculate:

(i) the work done by the man, and

(ii) the increase in his potential energy. (g = 9.8 m $s^{-2}$).

Answer 1

(i) Force exerted by the man = His weight,

$F=mg=50\times 9.8=490N$

Displacement, $s=10m$

So, work done, $W=F.s=490\times 10=4900J$

(ii) $m=50kg$
$h=10m$
$g=9.8m/s^2$

Increase in potential energy $=mgh=50\times 9.8\times 10=4900J$.