Question

a bullet of mass 4g when fired with a velocity of 50m/s can enter a wall upto a depth of 10cm how much will be the average resistence offered by the wall

Answer 1

Mass, m = 4g = 0.004 kg
Velocity, =  50cm/s = 0.5m/s
Distance, 10cm = 0.1m
The wall would have to resist the energy acquired by the bullet.

Kenetic Energy of bullet = Resistance offered by the wall.

1/2 mv²                        =  Resistance Force * Distance

(1/2) * 0.04 * 0.5 * 0.5 =  F * 0.1

0.5 * 0.04 * 0.5 * 0.5 =  F * 0.1

0.5 * 0.04 * 0.5 * 0.5/0.1 = F

0.05 = F

Therefore, Resistance offered by the wall = 0.05 N