$A$ body of mass $m$ accelerates uniformly from rest to $v_1$ in time $t_1$. As a function of time $t$,the instantaneous power delivered to the body is

$A$ constant force $F$ acts on a body of mass $m$ initially at rest. Which of the following graphs correctly represents the variation of the power $P$ developed with time $t$?

$A$ body of mass $1 \ kg$ begins to move under the action of a time-dependent force $\vec{F} = (t \hat{i} + 2t^2 \hat{j}) \ N$,where $\hat{i}$ and $\hat{j}$ are unit vectors along $x$ and $y$ axes. The power developed by the above force at time $t = 3 \ s$ will be: (in $W$)

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?

$A$ $750 \,W$ motor drives a pump which lifts $300 \,L$ of water per minute to a height of $6 \,m$. The efficiency of the motor is nearly (Take,acceleration due to gravity to be $10 \,m/s^2$) (in $\%$)

$A$ water pump rated $600 W$ has an efficiency of $95 \%$. If it is used to raise water through a vertical distance of $60 m$,what is the volume of water drawn in $20$ minutes (in $m^3$)? [Use density of water $= 1000 kg/m^3$,$g = 10 m/s^2$]