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?

The machine gun fires $240$ bullets per minute. If the mass of each bullet is $10 \ g$ and the velocity of the bullets is $600 \ ms^{-1}$, the power (in $kW$) of the gun is

$A$ quarter horsepower motor runs at a speed of $600 \text{ r.p.m.}$ Assuming $40\%$ efficiency,the work done by the motor in one rotation will be:

$A$ man of mass $50 \ kg$ carries an object to a height of $20 \ m$ in a time of $10 \ s$. The power used by the man in this process is $2000 \ W$. Find the mass of the object carried by the man (take $g = 10 \ m/s^2$). (in $kg$)

When a constant force is applied to a body moving with constant acceleration,power does not remain constant. For power to be constant,the force has to vary with speed as follows:

$A$ body of mass $m$ starts from rest and is accelerated uniformly to a velocity $v_1$ in time $t_1$. The instantaneous power delivered to the body as a function of time $t$ is: