The machine gun fires $240$ bullets per minute. If the mass of each bullet is $10 \mathrm{g}$ and the velocity of the bullets is $600 {\mathrm{ms}}^{-1}$, the power (in $\mathrm{KW}$) of the gun is

If a spring extends by $x$ on loading (if $T$ Is the tension in the spring and $k$ is spring constant), the energy stored by the spring is

A block of mass $50 \mathrm{kg}$ just slides over a distance of $1 \mathrm{m}$. If the coefficient of friction between their surfaces is $0.2$, the work done against friction is

A rod elongates by $l$ when a mass $M$ is suspended from it. The work done is ?

A bullet is fired from a rifle. If the rifle recoils, the K.E. of the rifle is

A force$\overrightarrow{F}=-k(y\hat{i}+x\hat{j})$  (where $k$ is positive constant) acts on a particle moving in the $xy$ plane. Starting from the origin, the particle is taken along the positive $x$-axis to the point ($a, 0$) and then parallel to the y-axis to the point ($a, a$). The total work done by the force $F$ on the particle is

A uniform chain of length $L$ and mass $M$ is lying on smooth table and one-third of its length is hanging vertically down over the edge of the table. If $g$ is the acceleration due to gravity, the work required to pull the hanging part on to the table is