Question

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 later in the pipe is 100 kg/m. What is the power of the engine?

(a) 400 W

(b) 200 w

(c) 100 W

(d) 800 w

Answer 1

Correct option  (d) 800 w

Explanation:

 Here, Mass per unit length of water,μ = 100 kg/m

Velocity of water, v = 2 m/s

Power of the engine,  P = μv³ = (100 kg/m)(2 m/s)³

^{=  800 W}