The average force necessary to stop a hammer having momentum $50 \ N-s$ in $0.25 \ s$ is ...... $N$.

$N$ number of balls,each of mass $m \ kg$,moving along the positive direction of the $x$-axis,strike a wall per second and return elastically. The velocity of each ball is $u \ m/s$. The force exerted on the wall by the balls in newtons is:

$A$ particle of mass $m$,initially at rest,is acted on by a force $F = F_0 \left\{ {1 - {{\left( {\frac{{2t - T}}{T}} \right)}^2}} \right\}$ during the interval $0 \leq t \leq T$. The velocity of the particle at the end of the interval is:

Displacement of a particle of mass $2\, kg$ moving in a straight line varies with time as $s = (2t^3 + 2)\, m$. The impulse of the force acting on the particle over a time interval between $t = 0$ and $t = 1\, s$ is .......... $N-s$.

$A$ bullet is fired from a gun. The force on the bullet is given by $F = 600 - 2 \times 10^5 t$,where $F$ is in newtons and $t$ is in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the impulse imparted to the bullet in $N-s$?

$A$ 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 $\,N-s$)