Question

Consider the following statements : 

(1) A light and a heavy body, having equal momenta, have equal kinetic energies. 

(2) The total energy of a body in motion is equal to the work it can do in being brought to rest. 

(3) A body cannot have momentum when its energy is zero. 

Which of these statement(s) is/are correct ? 

(a) (1) and (2) 

(b) (2) and (3) 

(c) Only (2) 

(d) Only (3) 

Answer 1

The correct option is: (d) Only (3)

Explanation:

Because they have equal momenta, hence equal mv, the heavy body will move very slowly and the light body will move very quickly. As Kinetic energy is 1 / 2 mv² . Thus the speed of the light body will be high giving higher kinetic energy to it in comparison to the kinetic energy of heavy body.