Final answer:
Most collisions are inelastic because kinetic energy is converted into other forms of energy, such as potential or thermal energy.
Step-by-step explanation:
Most collisions are inelastic because some amount of kinetic energy is converted into other forms of energy, such as potential energy, thermal energy or sound. In an inelastic collision, objects may stick together after impact and kinetic energy is not conserved, which indicates that there is an energy transformation. This contrasts with an elastic collision, in which kinetic energy is conserved. Collisions in the real world, like most automobile accidents, involve a combination of kinetic energy being transformed to other types of energy and less of it being removed when the objects do not stick together.