Question

A pump is used to lift $500kg$ of water from a depth of $80m$ in $10s$. Calculate the power at which the pump works. (Take $g=10m{s}^{-2}$)

• A. $400kW$
• B. $40kW$
• C. $0.4kW$
• D. None of the above

Answer 1

The correct option is B $40kW$

$Force=m\times g$
$F=500\times 10=5000N$
$Work=F\times s$.
$W=5000\times 80=4\times {10}^{5}joule$.
$Power=work/time$
$P=4\times {10}^5/10=4\times {10}^4=40kW$.