Question

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

Answer 1

The correct answer is:
A) All the mechanical energy of the carousel is lost. 

In fact, all the mechanical energy of the carousel is lost because of the friction between the carousel and the ground. The carousel loses its energy little by little because of the friction, and it gradually slows down until it stops: all the initial energy of the carousel has been dissipated into thermal energy due to the friction between the carousel surface and the ground.

Answer 2

Answer:

D) Mechanical systems need an external energy source to maintain their

Explanation:

Mechanical systems need an external energy source to maintain their motion.

In this case, electrical energy is transformed to mechanical energy. Without electrical energy, the carousel slows due to friction and eventually stops.