Complete the statement. Assume that Alec's mass did not change.
The gravitational potential energy stored between Alec and Earth () as he hiked toward the summit.

 - stayed the same
 - decreased
 - increased
Think about how the distance between Alec and the center of Earth changed.
The summit of the mountain was higher than the point where Alec started hiking. As he hiked toward the summit, the distance between Alec and the center of Earth increased. So, the gravitational potential energy stored between Alec and Earth increased as he hiked toward the summit.