Question

A bullet of mass 10 g is fired from a rifle with a velocity of 800 m/s. After passing through a mud wall 180 cm thick, the velocity drops to 100 m/s. Find the average force exerted by the wall.

Answer 1

Given, m = 10 g = 0.01 kg
u = 800 m/s
s = 180 cm = 1.8 m
v = 100 m/s
Retardation, $a=\frac{{800}^2-{100}^2}{2\times 1.8}=175000m/s^2$
$\therefore F=ma=0.01\times 175000=1750N$