Which one of the following is true?

Options

A. Both momentum and kinetic energy are conserved in all collisions
B. Neither momentum nor kinetic energy is conserved in inelastic collisions
C. Momentum is conserved in all collisions but not kinetic energy
D. Momentum is conserved in all collisions but kinetic energy is conserved only in inelastic collisions.

Answer

C

Explanation

This is an elastic head on collision between two bodies of equal masses, where `u_(1) =v` but `u_(2) = 0`.
In this case the first body will come to rest or v=0 and the body at rest, starts moving with velocity v.
[We experience this in carbon board play.]