An engine pumps water through a hose pipe. Water passes, through the pipe and leaves it with a velocity of 2 m/s. The mass per unit length of water in the pipe is 100 kg//m. What is the power of the engine ?

Options

A. 400 W
B. 200 W
C. 100 W
D. 800 W

Answer

D

Explanation

Here,
Mass per unit length of water, `mu = 100 kg//m`
Velocity of water, `v = 2 m//s`
Power of the engine, `P = mu v^3`
`= (100 kg//m) (2 m//s)^3 = 800 W`.