Dear neel,

Given that :

Initial velocity (u) = 150 m/s.

Final velocity (v)  =  0 m/s.

Time taken for the body to come at rest (t)= 0.03 sec.

Now according to newton's first law:

 v = u - at   -------------------------------------------  eq 1.

so from this equation value of :  a = (u/t).

Now from the euation we have :

s = ut - 1/2at² ----------------------------------------- eq 2.

put the values of u, t, a in the 2nd equation.

after solving we will get that :

s = 4.5m.

Thus the bullet will  penetrate 4.5 meters inside the wodden block.

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mass of bullet = 0.01 kg

initial vel ,u = 150 m/s

final vel , v= 0

time= 0.03s

distance = s

v=u+at

v2=u2+2as

use these eq to find a(accelaration) and s respectively .u will get the answer