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 $100\, kg/m$. Calculate the power $W$ of the engine. (in $, W$)

An electric pump is used to fill an overhead tank of capacity $9\,m^3$ kept at a height of $10\,m$ above the ground. If the pump takes $5\,minutes$ to fill the tank by consuming $10\,kW$ power,the efficiency of the pump should be : ............... $\%$ (Take $g = 10\,m/s^2$)

$A$ pump draws water from a tank which is $2.5\; m$ below the outlet and discharges it through a hose. The cross-sectional area of the hose is $10\; cm^{2}$,and the water leaves the end of the hose at a speed of $5\; m/s$. What is the power at which the pump is working (in $; W$)? (Assume $g = 10\; m/s^{2}$)

The power of a water pump is $2 \; kW$. If we take $g = 10 \; m/s^2$, how many liters of water can be raised to a height of $10 \; m$ in one minute?

$A$ constant power delivering machine has towed a box, which was initially at rest, along a horizontal straight line. The distance moved by the box in time $t$ is proportional to

$A$ constant force $F$ acts on a body of mass $m$ initially at rest. Which of the following graphs correctly represents the variation of the power $P$ developed with time $t$?