Which of the following describes an inelastic collision?

An inelastic collision is characterized by the fact that the colliding objects experience deformation and may stick together after the impact. This means that some of the kinetic energy of the system is transformed into other forms of energy, such as heat or sound, which accounts for the distortion of the objects. In this type of collision, the total kinetic energy before and after the collision is not conserved, making it distinct from elastic collisions where kinetic energy remains constant.

Additionally, the other options do not describe the nature of inelastic collisions accurately. First, the option stating that the colliding objects remain unchanged contradicts the definition, as inelastic collisions result in some permanent deformation. The assertion that the total kinetic energy increases also misrepresents inelastic collisions, since they typically result in a loss of kinetic energy. Finally, stating that the kinetic energy is conserved is fundamentally incorrect for inelastic collisions, as conservation of kinetic energy is a hallmark of elastic collisions instead. Thus, the choice that describes an inelastic collision accurately is the one stating that colliding objects become distorted and may stick together.