Question

what is the power of a pump which takes 10 second to lift 100 and of water tank situated at a height of 20m

Answer 1

here is your answer

Answer 2

time taken to lift 100Litre of water , t = 10sec

mass of water , m = volume of water × density of water

= 100 Litre × 1g/cm³

we know, 1Litre = 1000 cm³

so, mass of water , m = 100 × 1000 g

= 100 kg

and height, h = 20m

use formula, potential energy, P.E = mgh

= 100 × 10 × 20 [here, g = 10m/s² ]

= 20000 = 2 × 10⁴ J

now, power = energy/time

= 2 × 10⁴/10 = 2 × 10³ J/s = 2000 watt

hence, power of pump = 2000 watt