The human tail bone and appendix are examples of

A. Vestigial Organs- is the retention during the process of evolution of genetically determined structures or attributes that have lost some or all of their ancestral function in a given species.

When the ball is rising up, it gains kinetic energy. when the ball reaches the very top, it will have all potential energy, until it falls back down and gains it kinetic energy. finally when you catch the ball or it falls back down, it would have gained its potential energy back.