An engine is dragging a mass of $5000 \ kg$ with a velocity of $5 \ ms^{-1}$ along a smooth inclined plane of inclination $1$ in $50$. Then the power of the engine is (in $kW$)

$A$ man riding a bicycle moves at a speed of $7.2 \ km/hr$ up an incline having a length of $20 \ m$ and a height of $1 \ m$. The total mass of the man and the bicycle is $100 \ kg$. What is the power of the man in $W$?

An elevator in a building can carry a maximum of $10$ persons,with the average mass of each person being $68 \; kg$. The mass of the elevator itself is $920 \; kg$ and it moves with a constant speed of $3 \; m/s$. The frictional force opposing the motion is $6000 \; N$. If the elevator is moving up with its full capacity,the power delivered by the motor to the elevator $\left(g = 10 \; m/s^{2}\right)$ must be at least .............. $W$.

If a force $F$ is applied on a body and it moves with a velocity $v$,the power will be

$A$ water pump rated $600 W$ has an efficiency of $95 \%$. If it is used to raise water through a vertical distance of $60 m$,what is the volume of water drawn in $20$ minutes (in $m^3$)? [Use density of water $= 1000 kg/m^3$,$g = 10 m/s^2$]

Two men with weights in the ratio $4:3$ run up a staircase in time in the ratio $12:11$. The ratio of power of the first to that of second is