$A$ body of mass $M$ collides against a wall with a velocity $v$ and retraces its path with the same speed. The change in momentum is (take initial direction of velocity as positive).

How can the impulse of a force be determined when a large force acts on an object for a very short interval of time?

Which force acts on a body first: action or reaction?

$A$ particle of mass $2 \ kg$ is initially at rest. $A$ force acts on it whose magnitude changes with time. The force-time graph is shown below. The velocity of the particle after $10 \ s$ is $.... \ ms^{-1}$.

$A$ machine gun fires a bullet of mass $40\,g$ with a velocity $1200\,m/s$. The man holding it can exert a maximum force of $144\,N$ on the gun. How many bullets can he fire per second at the most?

$100$ balls,each of mass $m$,moving with speed $v$,simultaneously strike a wall normally and are reflected back with the same speed in time $t$. The total force exerted by the balls on the wall is