Question

A bullet is fired from a gun.If the recoils freely ,then kinetic energy of bullet is:
(1)Less than that of gun
(2)More than that of gun
Give reason for your answer.

Answer 1

according to conservation  of momentum
momentum of gun=momentum of bullet
as momentum=mass x velocity
as mass of bullet of is less than mass of gun
therefore velocity of bullet is more than velocity of gun
as K.E=1/2 x m x v x v
           =1/2 x momentum of gun x velocity of bullet
therefore K.E OF BULLET IS MORE THAN OF K.E OF GUN

          

Answer 2

More than that of gun