Question

Calculate the power of an electric pump that can lift $600\text{kg}$ of water from the ground into a tank placed at a height of $1200\text{cm}$ in $10$ seconds.

• A. $2\text{kW}$
• B. $6\text{kW}$
• C. $7.2\text{kW}$
• D. $9.6\text{kW}$

Answer 1

The correct option is C $7.2\text{kW}$

Given,
Mass, $\text{m}=600\text{kg}$
Height, $\text{h}=1200\text{cm}=12\text{m}$
Time taken, $\text{T}=10\text{s}$
Energy consumed by the pump to lift water, $\text{E}=\text{mgh}$
$\text{E}=600\times 10\times 12$
$\text{E}=72,000\text{J}$

The power of the pump, $\text{P}=\frac{\text{E}}{\text{T}}$
$=\frac{72,000}{10}=7200\text{W}=7.2\text{kW}$