$A$ machine gun fires a bullet of mass $40$ g with a speed of $600$ m/s. The person holding the gun can bear a maximum force of $168$ $N$ on it. The number of bullets that can be fired from the gun per second is

In the figure given below,the position-time graph of a particle of mass $0.1 \,kg$ is shown. The impulse at $t = 2 \,s$ is .......... $kg \,m \,s^{-1}$.

$A$ machine gun can fire $200$ bullets $\min^{-1}$. If $35 \ g$ bullets are fired at a speed of $750 \ m \ s^{-1}$, the average force exerted by the gun on the bullets is, (in $N$)

$A$ bullet of $4 \, g$ mass is fired from a gun of mass $4 \, kg$. If the bullet moves with the muzzle speed of $50 \, ms^{-1}$,the impulse imparted to the gun and the velocity of recoil of the gun are:

$A$ 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:

Why can it be said that there is no such thing as an isolated force in nature?