You hop on the carousel horse. the attendant flips the switch and you move up and down, around and around. when the ride ends, the attendant again flips the switch. the up and down motion stops, as you continue to move in a circular motion, gradually slowing to a stop. why? a) all the mechanical energy of the carousel is lost. b) all of the kinetic energy is converted to potential energy. c) the external energy source overcomes the internal energy of the carousel. d) mechanical systems need an external energy source to maintain their