Question

10. A pump lifted 50.0 kilograms of water at a constant velocity a vertical distance of 10.0 meters in 75.0 seconds. Theaverage power consumption of the pump is(a) 6.67 W(b) 16.7 W(c) 32.7W(d) 65.4 W

Answer 1

Given,

Mass of the water, m=50.0 kg

Height to which water was lifted, Δh=10.0 m

Time taken to pump the water, t=75.0 s

The work done to lift the water is given by the change in the potential energy of the water

i.e.

`W=mg\Delta h`

Where g is the acceleration due to gravity.

On substituting known values in the above equation,

`W=50.0*9.8*10.0=4900.0\text{ J}`

Power is given by

`P=(W)/(t)`

Substituting the known values,

`P=(4900.0)/(75.0)=65.3\text{ W}\approx65.4\text{ W}`

Therefore the power consumption of the pump is 65.4 W