The linear momentum of a particle is defined as the product of the mass of the particle times the velocity of that particle. Conservation of momentum of a particle is a property exhibited by any particle where the total amount of momentum never changes.

Conservation of linear momentum 8v=2v1+ 8v2

Definitionof coefficient of Restitution v2− v1/v − 0 = −1

⇒ v2− v1= −v

Solving these equations,we get v2= 0.6v

Final KE = 1/2m(0.6v)2 = 0.36KE

The principle of conservation of momentum states that if two objects collide, then the total momentum before and after the collision will be the same if there is no external force acting on the colliding objects.