संघट्ट के पश्चात् जब दो पिण्ड एक साथ चिपक

In perfectly inelastic collision, the two colliding bodies gets stuck together and move with a common velocity.

For perfectly inelastic collision, $e=0$

In perfectly inelastic collision, total momentum of the system remains conserved just before and just after the collision but some kinetic energy is lost during the collision.