The average force necessary to stop a hammer with momentum $p \; Ns$ in $0.5 \; s$ is .......... $N$.

$N$ bullets,each of mass $m \, kg$,are fired with a velocity $v \, m/s$ at the rate of $n$ bullets per second upon a wall. The reaction force offered by the wall to the bullets is given by:

Why does a child feel more pain when she falls down on a hard cement floor,than when she falls on the soft muddy ground in the garden?

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 ......... $s$.

$A$ $100 \, g$ 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 ............. $N$.

$A$ machine gun fires a bullet of mass $35 \ g$ with a speed of $600 \ m/s$. The person holding the gun can exert a maximum force of $147 \ N$ on it. The number of bullets that can be fired from the gun per second is