$A$ body of mass $50 \, g$ has a velocity of $20 \, cm/s$. If a constant force of $50 \, dyne$ acts on it,what will be its momentum after $5 \, s$?

$A$ 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).

$A$ machine gun fires bullets of mass $30 \text{ g}$ with a velocity of $1000 \text{ m/s}$. The man holding the gun can exert a maximum force of $300 \text{ N}$ on it. How many bullets can he fire per second at most?

The magnitude of force acting on a particle moving along the $x$-axis varies with time $(t)$ as shown in the figure. If at $t=0$ the velocity of the particle is $v_0$,then its velocity at $t=T_0$ will be

$A$ $100 \, g$ iron ball having a velocity of $10 \, m/s$ collides with a wall at an angle of $30^\circ$ with the wall surface and rebounds with the same angle. If the period of contact between the ball and the wall is $0.1 \, s$,then the force experienced by the ball is ............. $N$.

An athlete runs for some distance before taking a long jump. Why?