A pump on the ground floor of a building can pump up water to fill a tank of volume 30m3 in 15min. If the tank is 40m above the ground, and the efficiency of the pump is 30%, how much electric power is consumed by the pump ?[Dencity of water 103kgm−3](g=9.8ms−2)
Given:
Volume of the tank, V=30m3
Time of operation, t=15min=15×60=900s
Height of the tank, h=40m
Efficiency of the pump, =30 %
Density of water, =103kg/m3
Mass of water, m=30×103kg
Output power can be obtained as:
P0=Work doneTime=mght
=30×103×9.8×40900=13.067×103W
For input power Pi, efficiency is given by the relation:
PoPi=30%
Pi=13.067×100×10330
Pi=43.6kW