Question

A bullet slows down after penetrating a block of wood find velocity of block

Answer 1

formula to be used :- v2 = u2-2as;

v = final speed = 0

u = initial speed = 600 m/s

a = retardation;

s = distance travelled by bullet in wooden block = 0.6 m

 

retardation = (600×600)/(2×0.6);

resistive force = mass of bullet × retardation = 0.03 ×(600×600)/(2×0.6) = 9000 N

Answer 2

a bullet is fired so initial velocity
(u)= u m/s

when it penetrates so final velocity
(v)= v m/s

all this action happens in time
(t)= t sec.

hence, velocity =
v = u + a × t