When a constant force is applied to a body moving with constant acceleration,power does not remain constant. For power to be constant,the force has to vary with speed as follows:

$A$ weight lifter lifts $300 \ kg$ from the ground to a height of $2 \ m$ in $3 \ s$. The average power generated by him is $... \ W$.

$A$ body of mass $2 \ kg$ begins to move under the action of a time-dependent force given by $\overrightarrow{F} = (6t \hat{i} + 6t^2 \hat{j}) \ N$. The power developed by the force at time $t$ is given by:

From a waterfall,water is pouring down at the rate of $100 \,kg/s$ on the blades of a turbine. If the height of the fall is $100 \,m$,the power delivered to the turbine is approximately equal to .......... $kW$.

$A$ body of mass $4 \ kg$ is placed on a plane at a point $P$ having coordinates $(3, 4) \ m$. Under the action of force $\overrightarrow{F} = (2 \hat{i} + 3 \hat{j}) \ N$,it moves to a new point $Q$ having coordinates $(6, 10) \ m$ in $4 \ s$. The average power and instantaneous power at the end of $4 \ s$ are in the ratio of:

An electric motor exerts a force of $40\, N$ on a cable and pulls it by a distance of $30\, m$ in one minute. The power supplied by the motor is .............. $W$