Question

A water pump can fill a 500-litre water tank kept at 6 m height in 50 minutes. What is the power of the pump ? (g = 10 m/s2) (A) 10 Watt (B) 30 Watt 5 Watt (D) 15 Watt ​

Answer 1

Given info : A water pump can fill a 500-litre water tank kept at 6m height in 50 minutes.

To find : the power of the pump is ...

solution : the power of the pump = total energy consumed by pump in 50 minutes.

       = potential energy of water/time taken

       = mgh/t

here the volume of water in the tank = 500 litre = 500 × 1000 cm³ = 5 × 10⁵ cm³

mass of water , m = volume × density of water

                              = 5 × 10⁵ cm³ × 1 g/cm³ = 5 × 10⁵ g = 500 Kg

height, h = 6 m

acceleration due to gravity , g = 10 m/s²

time, t = 50 min = 50 × 60 sec = 3000 sec

now the power of the pump = (500 Kg × 10 m/s² × 6m)/3000sec

                                              = 30 W

therefore the power of the pump is 30W.