A bullet travelling with a velocity of 16 m/s penetrates a tree trunk and comes to rest in 0.4 m. Find the time taken during the retardation.

Explanation

`u=16m/s (initial)
v=0
S=0.4m
Deceleration
a= (v^2-u^2)/(2S)
(0-16^2)/(2xx0.4)
=320m/s^2
time= (v-u)/a=
(0-16).(-320)
=0.05 sec`