Two-Body Elastic Collisions

An elastic collision is defined as a collision in which no kinetic energy is lost during the interaction. In contrast, an inelastic collision is one where a portion of the kinetic energy is converted into other forms of energy, such as internal energy or heat. Inelastic collisions are common in everyday life, where energy transformation occurs during impact. In certain situations, such as molecular collisions in low-pressure hot gases, collisions approach perfect elasticity, meaning little to no kinetic energy is lost. Similarly, some large-scale interactions, like those between satellites and planets, can be considered nearly perfectly elastic. The assumption of conservation of momentum and conservation of kinetic energy makes the calculation of final velocities in two-body collisions possible.