a collision in which the total kinetic energy of the colliding bodies or particles is the same after the collision as it was before (opposed to inelastic collision).
A collision between bodies in which the total kinetic energy of the bodies is conserved. In a perfectly elastic collision, no energy is dissipated as heat energy internal to the bodies, and none is spent on permanently deforming the bodies or radiated away in some other fashion. Elastic collisions, such as the collision of a rubber ball on a hard surface, result in the reflection or bouncing of bodies away from each other. Comapre inelastic collision.
