The source calls a collision perfectly inelastic under one specific condition. What reduces internal kinetic energy more than any other type of inelastic collision?

1. The source names a special case of inelastic collision where the objects end up sharing a single final velocity. 2. A collision in which the objects stick together is sometimes called perfectly inelastic. 3. It reduces internal kinetic energy to the minimum value it can have while still conserving momentum, more than any other type of inelastic collision. 4. Bouncing apart, passing through each other, or gaining kinetic energy describe different outcomes, none of which is the perfectly inelastic case the source defines. _Source: OpenStax College Physics (CC BY 4.0), Ch 8 "Linear Momentum and Collisions", section 8.5 Inelastic Collisions in One Dimension_