Question

A pump of power 800 W stores 200 kg water at a height of 10 m. What is the time taken by the pump to lift water to this height?
$[Takeg=10m/s^2]$

• A. 25 s
• B. 20 s
• C. 30 s
• D. 17 s

Answer 1

The correct option is A 25 s

Power, $P=800WP=\frac{\text{Work done (W)}}{\text{Time taken (t)}}$

Time taken, $t=\frac{W}{P}...\left(i\right)$

Work done in lifting water of mass 200 kg to 10 m height,

$W=mgh=200\times 10\times 10=20,000Jt=\frac{W}{P}=\frac{20,000}{800}=25s$

$\therefore$ Time taken by the pump to lift the water upto height h,

Hence, the correct answer is option (a).