## Item NG095002: The total amount of energy a ball has does not change after it goes down and up a dip because the total energy of the system (ball and track) does not change (assuming no energy transfer between the ball and the track and the ball and the air around it).

Imagine a ball on a track where no energy is transferred between the ball and the track or between the ball and the air around it.  The ball goes past Position 1, then down and up a dip on the track, and past Position 2.  Position 1 and Position 2 are at the same height.

Will the total amount of energy the ball has at Position 2 be more, less, or the same as the total amount of energy the ball had at Position 1 and why?  (Remember that no energy is transferred between the ball and the track or between the ball and the air around it.)

1. The total amount of energy the ball has will be more at Position 2 because new energy was made when the ball went down the long side of the dip.
2. The total amount of energy the ball has will be less at Position 2 because energy was used up when the ball went up the steep side of the dip.
3. The total amount of energy the ball has will be the same at Position 1 and Position 2 because the total amount of energy in the system (ball and track) did not change.
4. Whether the total amount of energy of the ball is more, less, or the same at Position 2 compared to Position 1 depends on the speed of the ball before it got to the dip.