Inelastic collisions occur when two objects collide and do not bounce apart completely. Instead, they stick together or deform, resulting in a loss of kinetic energy. This energy is transformed into other forms, such as heat or sound, rather than being conserved as motion. A common example of an inelastic collision is a car crash, where the vehicles crumple upon impact. In this case, the combined mass of the cars moves together after the collision, demonstrating that some energy has been lost in the process. Inelastic collisions are important in understanding real-world interactions in physics.