Question

A bullet fired into a fixed target
loses half of its velocity after
penetrating 3cm. How much further
it will penetrate before coming to
rest assuming that if faces constant
resistance to motion?
(a) 1.5 cm (b) 1.0 cm
(c) 3.0 cm
(d) 2.0 cm​

Answer 1

Explanation:

Correct option is

D

1.0cm

Applying the work-energy theorem for the bullet:

The total kinetic energy of bullet = work done by regarding force + Final kinetic energy of the bullet.

21mv02=f(3cm)+21m(2v0)2

83mv02=f(3cm)...(i)

Now to find the distance covered to come to rest can be obtained as:

21mv02=f(l.cm)....(ii)

Now equating the equation (I) and (II):

3l=21.38⇒l=4cmΔl=4−3=1cm