$A$ car of mass $m$ has an engine which can deliver power $P$. The minimum time in which the car can be accelerated from rest to a speed $v$ is .............

$A$ lift raises $50$ passengers, each having an average weight of $600 \,N$, to a height of $100 \,m$ at a constant speed in time $t$. If the average power of $15 \,kW$ is required by the lift, then the value of $t$ in seconds is:

$A$ force applied by an engine of a train of mass $2.05 \times 10^6 \; kg$ changes its velocity from $5 \; m/s$ to $25 \; m/s$ in $5$ minutes. The power of the engine is ........... $MW$.

Water is pumped from a depth of $10 \ m$ and delivered through a pipe of cross-section $10^{-2} \ m^2$. If it is needed to deliver a volume of $10^{-1} \ m^3$ per second,the power required will be ........ $kW$.

$A$ car of mass $m$ moving with velocity $u$ on a straight road in a straight line, doubles its velocity in time $t$. The power delivered by the engine of the car for doubling the velocity is

$A$ car of mass $m$ is accelerating on a level smooth road under the action of a single force $F$. The power delivered to the car is constant and equal to $P$. If the velocity of the car at an instant is $v$,then after travelling how much distance does its velocity become double?