A bullet is fired from a rifle and the rifle recoils , Kinetic energy of rifle is

Options

A. less than K.E of bullet
B. grater than K.E of bullet
C. equal to K.E of bullet
D. none of the above

Answer

B

Explanation

Momentum of rifle = Momentum of bullet
`m_(1)v_(1) = m_(2) v_(2) ` , Also `m_(1) gt m_(2)`
`(K.E. "of rifle")/(K.E. "of bullet") = ((1)/(2) m_(1) v_(1)^(2))/((1)/(2) m_(2) v_(2)^(2))`
= `(m_(1)^(2) v_(1)^(2))/(m_(1)) * (m_(2))/(m_(2)^(2) v_(2)^(2)) = (m_(2))/(m_(1))`
K.E. of rifle is less than K.E. of bullet .