Question: Which investigation might be used to demonstrate potential energy?

  Options: 
 A. Roll one ball toward another, and see what happens when they collide.
 B. Place a glass of water in the freezer, and see how long the water takes to become solid.
 C. Compress a spring by different amounts, and see how far it can launch a ball into the air.
 D. Roll a ball from the top of an inclined plane and determine the amount of time it takes to get to the bottom.
Answer: C