In physics, collisions between objects can be classified as either elastic or inelastic. These classifications depend on the conservation of kinetic energy and the behavior of the objects involved. Let's take a closer look at the differences between the two.

Elastic Collisions: In an elastic collision, both momentum and kinetic energy are conserved. This means that the total kinetic energy of the system before the collision is equal to the total kinetic energy after the collision. In other words, the objects involved in an elastic collision bounce off each other without any permanent deformation. A classic example of an elastic collision is the collision between two billiard balls.

Inelastic Collisions: In an inelastic collision, only momentum is conserved, while kinetic energy is not. This means that the total kinetic energy of the system before the collision is not equal to the total kinetic energy after the collision. In an inelastic collision, the objects involved stick together or experience some level of deformation. A common example of an inelastic collision is a car crash.

The behavior of objects in collisions can be further quantified using the concept of the coefficient of restitution, denoted by the symbol e. This coefficient measures the elasticity of a collision and can have values between 0 and 1. A value of 1 represents a perfectly elastic collision, while a value of 0 represents a perfectly inelastic collision.