Question

A pump is required to lift $800\text{kg}$ of water per minute from a $10\text{m}$ deep well and eject it with speed of $20\text{m/s}$. The power required (in watts) of the pump will be
(Take $g=10m/s^2$)

• A. $6000$
• B. $4000$
• C. $5000$
• D. $8000$

Answer 1

The correct option is B $4000$

We know that the power,$P=\frac{W}{\Delta t}=\frac{mgh+\frac{1}{2}m{v}^2}{t}$

$($as $t=1\text{min})$

$=\frac{(800\times 10\times 10)+\frac{1}{2}\times 800\times (20{)}^2}{60}$
$=4000W$

Hence option B is the correct answer