Question

A pump is used to lift $500kg$ of water from a depth of $80m$ in $10s$.

(Take $g=10m{s}^{-2}$). Calculate the work done by the pump.

• A. $16\times {10}^{5}J$
• B. $4\times {10}^{5}J$
• C. $4\times {10}^{8}J$
• D. $2\times {10}^{5}J$

Answer 1

The correct option is B $4\times {10}^{5}J$

Given,

Mass of water lifted, $m=500kg$

Displacement, $d=80m$

Time taken, $t=10s$

Force, $F=m\times g$

$F=500\times 10$

$F=5000N$

Work done, $W=F\times d$

$W=5000\times 80$

$W=4\times {10}^{5}J$.