$A$ 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?

The time in which a force of $2 \, N$ produces a change of momentum of $0.4 \, kg \cdot m/s$ in a body is ......... $s$.

The $F-t$ graph for an object is shown in the figure. What will be the magnitude of the change in momentum $(\Delta p)$ in the interval of $0.03\, s$ from the start?

$A$ $4 \ kg$ disk slides over level ice toward the east at a velocity of $1 \ m/s$,as shown. The disk strikes a post and rebounds toward the north at the same speed. The change in the magnitude of the eastward component of the momentum of the disk is ............. $kg \cdot m/s$.

$A$ jet of water with cross-sectional area $A$ strikes a wall at an angle $\theta$ with the normal to the wall and rebounds elastically. If the density of water is $\rho$ and the velocity is $v$,what is the force exerted on the wall?

Three different projectiles,each with the same mass $m$,are fired with speed $v$ at a wall. In case $A$,the projectile bounces straight back with speed $v$. In case $B$,the projectile sticks to the wall. In case $C$,the projectile crashes through the wall and emerges with half its original speed. These three cases are shown in the figure. Place the magnitude of the impulse exerted by the wall on the projectile in each of these three cases in the correct order.