Question

A pump is required to lift 1000 kg of water per minute from well of 20 m deep and eject it at a rate of 20ms what(horsepower engine is required for the purpose of lifting water

Answer 1

$<i>$
1000 kg of water is to be lifted per minute.

So, weight of water to be lifted is = 1000×9.8 = 9800 N

Work done in lifting this weight of water from depth ‘20m’ is = 9800x20=196000 J

Now the 1000 kg that is lifted is ejected with speed 20 m/s.

So, work done in giving it the kinetic energy is = ½ × 1000 × 202 = 200000 J

So, total work done is = (196000+ 20000) = 396000 J

This work is done in 1 minute or 60 s.

So, power of engine is = (396000)/60 W = 6600W

1 Watt = 746 horsepowers
Thus, the power in hp is = 6600 x 746 hp

= 4923600 hp