$A$ car of mass $m$ is driven with acceleration $a$ along a straight level road against a constant external resistive force $R$. When the velocity of the car is $V$,the rate at which the engine of the car is doing work will be

$A$ body at rest is moved along a horizontal straight line by a machine delivering a constant power. The distance moved by the body in time $t$ is proportional to :

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 elevator lifts a load of $500 \ kg$ with a constant speed of $0.4 \ m/s$. What is the minimum horsepower $(H.P.)$ of the motor required?

$A$ vehicle of mass $m$ starts from rest and accelerates. If the engine delivers a constant power $P$,then the position $s$ of the vehicle at time $t$ is given by:

$A$ body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time $t$ is proportional to