In $12\mathrm{.}1$s$,240$ bullets strike and embed themselves in a wall. The bullets strike the wall perpendicularly. Each bullet has a mass of $5$ x

$10-3$ kg and a speed of $1390$ m$/$s$.($a$)$ What is the average change in momentum per second for the bullets? $($b$)$ Determine the average

force exerted on the wall. $($c$)$ Assuming the bullets are spread out over an area of $2\mathrm{.}95$ x $10-4$ m$?$ obtain the average pressure they exert

on this region of the wall.