A girl weighing $400\ N$ climbs a vertical ladder. If the value of $g$ be $10\ ms^{-2}$, the work done by her after climbing $2\ m$ will be:
(a) $200\ J$
(b) $800\ J$
(c) $8000\ J$
(d) $2000\ J$

Academic Physics NCERT Class 9

Weight of the girl $mg=400\ N$

Height $h=2\ m$

So, the work done by the girl to climb $W=mgh$

$=400\ N\times2\ m$

$=800\ J$

So, option (b) is correct.

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Updated on: 10-Oct-2022

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