Momentum & Collisions

Conservation of momentum in elastic and inelastic collisions

The law of conservation of momentum states that the total momentum of an isolated system remains constant regardless of internal interactions. In elastic collisions, both momentum and kinetic energy are conserved. In perfectly inelastic collisions, objects stick together — momentum is still conserved but kinetic energy is not (it converts to heat/deformation). The coefficient of restitution e ranges from 0 (perfectly inelastic) to 1 (perfectly elastic).