Question

1.
If a bullet of mass 5 gm moving with velocity 100 m /sec.
penetrates the wooden block upto 6 cm. Then the average
force imposed by the bullet on the block is (MP PMT 2003)
(a) 8300 N
(b417 N
(c) 830 N
(d) Zero​

Answer 1

Answer:

(b) 417 N

Explanation:

u=100m/s m=5gm=0.005kg

v=0 at s=6cm=0.06m as after 6cm the bullet stops,

so using, v^2 = u^2 +2as

(0)^2= (100)^2 +2a(0.06)

a= (-10000)/0.12

a=(-83333.33) m/s^2

now force,F=ma

F=0.005×(-83333.33)

=(-416.666)N

=(-417)N approximately

here the minus sign represents that the force is acting against the motion of the body.

so average force will be 417N.