In an elastic collision, both kinetic energy and linear momentum are conserved. This means that:
- The total kinetic energy before the collision is equal to the total kinetic energy after, and
- The total momentum of the system remains unchanged throughout the interaction.
Elastic collisions are idealized and most commonly occur in systems where objects bounce off each other without any loss of energy to sound, heat, or deformation.
Examples of nearly elastic collisions include:
- Collisions between gas molecules in a sealed container,
- Steel ball bearings in Newton’s cradle,
- Some atomic and subatomic particle interactions.
In contrast, inelastic collisions involve some loss of kinetic energy (e.g., due to heat or deformation), though momentum is still conserved.
Elastic collisions are key to understanding molecular motion in gases, and they serve as a fundamental principle in both classical mechanics and statistical physics.