Question

A bullet travelling with



velocity of 16 m/s



penetrates a tree trunk and



comes to rest in 0.4 m. find



the time taken during the



retardation.

Answer 1

first we will calculate acceleration

v^2 - u^2 = 2as

v= 0 (it comes to rest)

u = 16

a = ?

s = 0.4

0 - 16*16 = 2*a*0.4

-256 = 0.8a

-256/0.8 = a

-320 = a

now we will find the time taken

v= u+at

v= 0(rest)

u =16

a = -320

t=?

0 = 16 + -320*t

320t = 16

t = 16/320

t = 0.05seconds