Question

In an elastic collision of two particles the following quantity is conserved

A.)momentum of each particle. B.) Speed of each particle

C.) kinetic energy of each particle

D.) total kinetic energy of both the particles

Answer 1

An elastic collision is defined as one in which both conservation of momentum and conservation of kinetic energy are observed. This implies that there is no dissipative force acting during the collision and that all of the kinetic energy of the objects before the collision is still in the form of kinetic energy afterward..
So, for an elastic collision , both momentum, and kinetic energy are conserved.

But but conservation of momentum and KE, we mean total momentum and total KE of system, ie,of both particles.

So, answer is total kinetic energy of both particles
D.) total kinetic energy of both the particles


You can see equations to understand this.
So, answer is