An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a veloci

Question

An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of $2 \mathrm{~m} / \mathrm{s}$. The mass per unit length of water in the pipe is $50 \mathrm{~kg} / \mathrm{m}$. What is the power of the engine?\

Professor PC Thomas Classes · Answer

Here, Mass per unit length of water, $\mu=50 \mathrm{~kg} / \mathrm{m}$\ Velocity of water, $v=2 \mathrm{~m} / \mathrm{s}$\ Power of the engine, $P=\mu v^{3}$ 
$ =(50 \mathrm{~kg} / \mathrm{m})(2 \mathrm{~m} / \mathrm{s})^{3}=400 \mathrm{~W} $