Question

Ignoring any friction, how are kinetic and potential energy related to each other as the ball swings back and forth? As the ball moves upward, both kinetic and potential energy decrease. As the ball moves downward, both kinetic and potential energy increase. As the ball moves upward, kinetic energy decreases and potential energy increases. As the ball moves downward, kinetic energy decreases and potential energy increases.

Answer 1

At an end point the ball need potential energy(energy from inside) to keep on going and it also need kinetic energy(motion) which would result it in keep on moving. If it is attached to a rope and you swing it and it reaches one side to come back it will collect energy from itself and then boost it into kinetic energy.