The power of a water pump is 2 kW. The amount of water (in litres) it can raise in one minute to a height of 10 m will be :

(g = 10 m/s2)

Concept:

Power is the rate of doing work or work done per unit time.

Calculation:

Given:

Power of pump = 2kW = 2000 W, Time (t) = 60 sec

Height (h) = 10 m, g = 10 ms^-2 

Here the work done is raising of water upto height h.

Work Done = Raising of water = Increase in Potential Energy

Work Done = mgh = m × 10 × 10 ⇒ 100m (Joule)

∴ m = 60 × 20 = 1200 kg

Hence, the pump can raise 1200 kg of water per minute up to 10 m in height.