Question

A pump is used to lift 500kg of water from a depth of 80m in 10s. Calculate:
(i)the power rating of the pump it its efficiency is 40%. (Take g=10ms².)

Answer 1

The power rating of the pump will be 100 KW

Explanation :

Given,

mass of water = 500 kg

depth = 80 m

g = 10 m/s²

t = 10 sec

Hence work done in lifting water = weight x distance

=> W = mgh

=> W = 500 x 10 x 80 = 400000

Power = work/time

=> P = w/t = 400000/10 = 40000 watt = 40 KW

Since efficiency of the pump = 40% = 0.4

=> power output/power input = 0.4

=> 40/Power input = 0.4

=> Power input = 40/0.4 = 100 KW

Hence the power rating of the pump will be 100 KW

Answer 2

Explanation:

here is your answer

ICSE physics question