An engine develops $20 kW$ of power. How much time will it take to lift a mass of $200 kg$ to a height of $40 m$ (in $s$)? $(g=10 m s^{-2})$

$A$ car of mass $m$ starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude $P_0$. The instantaneous velocity of this car is proportional to

$A$ body moves along a straight line under the action of a constant power delivered by an engine. The distance covered by the body in time $t$ is proportional to:

Two men have a weight ratio of $5 : 3$. If the ratio of the time taken by them to climb stairs is $11 : 9$,find the ratio of their power.

$A$ 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:

What average horsepower is developed by an $80 \; kg$ man while climbing in $10 \; s$ a flight of stairs that rises $6 \; m$ vertically?