Read the text about an object in motion. Dr. Chang teaches astronomy. She used to keep a model of Mars on the edge of
her desk, but one day she decided to hang it up so that her students could see it
better. She used a string to tie the model to a hook in the ceiling. A few days
later, the string came loose and the model fell to the ground.
When was the most gravitational potential energy stored between the model and Earth?
Assume that the model's mass did not change.
when the model was on the edge of Dr. Chang's desk
when the model was hanging from the hook
when the model was about to hit the ground