$A$ particle is acted upon by a force whose components' variations with time are shown in the diagrams. The magnitude of the change in momentum of the particle in $0.1\,s$ is:

$A$ boy hits a baseball with a bat and imparts an impulse $J$ to the ball. The boy hits the ball again with the same force,except that the ball and the bat are in contact for twice the amount of time as in the first hit. The new impulse equals:

The force $F$ acting on a particle of mass $m$ is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from $0 \, s$ to $8 \, s$ is .......... $N-s$.

$A$ block of mass $2 \ kg$ moves freely along the $x$-axis. It is at rest at $t = 0$. The force $F(t)$ acting on the block varies with time $t$ as shown in the figure. What is the kinetic energy of the block after $4.5 \ s$ (in $J$)?

An average force of $125\,N$ is applied on a machine gun firing bullets each of mass $10\,g$ at the speed of $250\,m/s$ to keep it in position. The number of bullets fired per second by the machine gun is:

$A$ body of mass $m$ collides against a wall with a velocity $v$ and rebounds with the same speed. Its change of momentum is