Question

if a bullet of 10 gram strikes a sand bag at a speed of 500 m per second and get embedded after travelling 5 cm. find (a)the resistive force exerted by the sand on the bullet (b) the time taken by the bullet to come at rest

Answer 1

m = 0.01 kg
u = 500 m/s
s = 0.05 m
v = 0 m/s
 
(b)t = s/u
=0.05/500
=0.0001 s

(a) F = ma
and a = (v-u)/t
so, a = (-) 500/0.0001
=-50000

F = -50000*0.01
=-500 N
here (-)ive sign shows retardation