Question

A pump can raise 1500liters of water per minute to a height of 21 meters. What must be the
H.P of the pump?​

Answer 1

Explanation:

First we convert the flow rate ΔV/Δt and the total head into compatible units:

1600 litres/minute = 0.02667 m 3 /s

21 metres head = 205,887 Pa

The pressure conversion could be done by simply calculating the weight mg of a column of water 21 metres high by 1 square meter in base area.

Then we can calculate water power:

P= (pressure)(flow rate)

=(205,887)(0.02667)

= 5491 watts (equivalent to 7.361 water horsepower)

At an efficiency of 75%, the motor requirement is:

P=7.3610.75

= 9.81 horsepower