An electric motor creates a tension of $4500 \, N$ in a hoisting cable and reels it in at the rate of $2 \, m/s$. What is the power of the electric motor?

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 $100\, kg/m$. What is the power of the engine $?$ ................ $W$

An elevator can carry a maximum load of $1800 \; kg$ (elevator $+$ passengers) and is moving up with a constant speed of $2 \; m s^{-1}$. The frictional force opposing the motion is $4000 \; N$. Determine the minimum power delivered by the motor to the elevator in watts as well as in horsepower.

An object is moving in a straight line under the influence of a source of constant power. If $v$ and $t$ are velocity and time respectively,then

$A$ body of mass $m$ is accelerated uniformly from rest to a speed $v$ in a time $T$. The instantaneous power delivered to the body as a function of time is given by

$1\,kWh$ is a unit of power. This statement is true or false? If it is wrong,then correct it.