A pump is required to lift `800 kg` of water per minute from a 10 m deep well and eject it with speed of `20 m//s` . The required power in watts of the pump will be

Explanation

`m=800kg,h=10m,v=20ms^(-1),t=60s`
Potential Energy P.E. = mgh = `800xx10xx10=8xx10^(4)J`
Kinetic energy = `KE=(1)/(2)mv^(2)=(1)/(2)xx800xx20xx20=16xx10^(4)J`
Total energy = `(8+16)xx10^(4)J=2.4xx10^(5)J`.
Power = `("total energy")/("time")=(2.4xx10^(5))/(60)=4xx10^(4)W`
`therefore P=40kW`.