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

$A$ soccer ball of mass $250 \text{ g}$ is moving horizontally to the left with a speed $22 \text{ ms}^{-1}$. This ball is kicked towards the right with a velocity $30 \text{ ms}^{-1}$ at an angle $53^{\circ}$ with the horizontal in the upward direction. Assuming that it took $0.01 \text{ s}$ for the collision to take place, the average force acting is $(\cos 53^{\circ} = \frac{3}{5}; \sin 53^{\circ} = \frac{4}{5})$. (in $\text{ N}$)

$A$ body whose momentum is constant must have constant

$A$ uniformly moving cricket ball is turned back by hitting it with a bat for a very short time interval. Show the variation of its acceleration with time (Take acceleration in the backward direction as positive).

$A$ cannon after firing recoils due to

$A$ 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?