The power of a crane, which lifts a mass of $1000 \text{ kg}$ to a height of $20 \text{ m}$ in $10 \text{ s}$ is: $(g = 9.8 \text{ ms}^{-2})$

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

$A$ man riding a bicycle moves at a speed of $7.2 \ km/hr$ up an incline having a length of $20 \ m$ and a height of $1 \ m$. The total mass of the man and the bicycle is $100 \ kg$. What is the power of the man in $W$?

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 .......... $kW$.

$A$ pump on the ground floor of a building can pump up water to fill a tank of volume $36 \,m^3$ in $30 \,min$. If the tank is $50 \,m$ above the ground, and the electric power consumed by the pump is $40 \,kW$, the efficiency of the pump is (Use $g=10 \,m / s^2$ and density of water $=1000 \,kg / m^3$ ) (in $\%$)

$A$ block of mass $10\, kg$ accelerates uniformly from rest to a speed of $2\, m/s$ in $20\, s$. The average power developed in the time interval of $0$ to $20\, s$ is .............. $W$.