An inelastic collision conserves the total momentum of the isolated colliding bodies but converts some of their kinetic energy into internal energy. The decrease in translational kinetic energy drives dissipative spreading of a planetary ring.
Articles by others on the same topic
An inelastic collision is a type of collision in which the total kinetic energy of the system is not conserved, although the total momentum is conserved. Inelastic collisions occur when two objects collide and become deformed, stick together, or otherwise interact in a way that some of the kinetic energy is transformed into other forms of energy, such as heat, sound, or internal energy. In perfectly inelastic collisions, the colliding objects stick together after the collision and move as a single entity.