$A$ 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 $\,N-s$)

$A$ body of mass $M$ hits normally a rigid wall with velocity $V$ and bounces back with the same velocity. The impulse experienced by the body is

$A$ golf ball of mass $50 \text{ g}$ placed on a tee is struck by a golf club. The speed of the golf ball as it leaves the tee is $100 \text{ m/s}$, and the time of contact with the ball is $0.02 \text{ s}$. If the force decreases to zero linearly with time, then the force at the beginning of the contact is (in $\text{ N}$)

$A$ ping-pong ball of mass $m$ is floating in air by a jet of water emerging out of a nozzle. If the water strikes the ping-pong ball with a speed $v$ and just after collision the water falls dead,the rate of flow (in $kg/s$) of water in the nozzle is equal to

$A$ ball of mass $50 \,g$ is dropped from a height of $20 \,m$. $A$ boy on the ground hits the ball vertically upwards with a bat with an average force of $200 \,N$,so that it attains a vertical height of $45 \,m$. The time for which the ball remains in contact with the bat is ........... of a second. [Take $g = 10 \,m/s^2$]

$A$ time-varying force acts on a ball of mass $100 \ g$ for $2 \ ms$. The force versus time curve is shown below. If the initial speed of the ball is $10 \ m \ s^{-1}$,then the speed of the ball after $2 \ ms$ is: (in $m \ s^{-1}$)