If the bodies collide and stick together, the. collision is called perfectly inelastic. In this case, much of the kinetic. 3Notice there is no arrow over the velocity variable in the equation for kinetic energy. Last updated October 5, 2014 55. 5. Inelastic Collisions. energy is lost in the collision. That is, much of the kinetic energy is converted. to other forms of energy. In the following two experiments you will be dealing with a perfectly. inelastic collision in which much of the kinetic energy is lost, and with a. nearly elastic collision in which kinetic energy is conserved.