An object of mass $m \, kg$ with speed $v \, m/s$ strikes a wall at an angle $\theta$ with the normal and rebounds at the same speed and same angle. The magnitude of the change in momentum of the object will be

$A$ 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).

Two trains $A$ and $B$ are running in the same direction on parallel rails such that $A$ is faster than $B$. Packets of equal weight are transferred between them. What will happen due to this?

$A$ bob of mass $10m$ is suspended through an inextensible string of length $l$. When the bob is at rest at the equilibrium position, two particles of mass $m$ each, moving with velocity $u$, strike the bob at an angle of $60^{\circ}$ with the string and get simultaneously attached to it. What is the value of the impulsive tension $J$ in the string during the impact?

$A$ cricket ball of mass $250\, g$ collides with a bat with velocity $10\, m/s$ and returns with the same velocity within $0.01\, s$. The force exerted on the ball is ....... $N$.

$A$ ball of mass $0.1 \,kg$ strikes a wall normally with a speed of $30 \,ms^{-1}$ and rebounds with a speed of $20 \,ms^{-1}$. The impulse of the force exerted by the wall on the ball is (in $\,N-s$)