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 180cm thick, the velocity drops to 100m/s. calculate the average resistance of the wall.

Answer 1

Given:

mass of the bullet = 10 g or 0.01 kg

Initial velocity = 800 m/s

Final velocity = 100m/s.

thickness of the mud wall, s = 180cm or 1.8 m

Now from the Newton's third equation of motion we can calculate the retardation caused in the bullet because of mud wall

2as = v² – u²

a = -175000 m/s²

Average resistance of the wall = ma = 1750N and will act against the motion of the bullet.