Question

when riding a roller coaster, you go up and down many hills. as you get to the top of a roller coaster, what energy change is taking place.
heat energy is changed into chemical energy.
chemical energy is changed into heat energy.
potential energy is changed into kinetic energy.
kinetic energy is changed into potential energy.

Explanation:

To determine the energy change at the top of a roller coaster, we analyze the concepts of kinetic and potential energy. Kinetic energy ($KE$) is energy of motion, and potential energy ($PE$) is stored energy (e.g., due to height). As the roller coaster approaches the top of a hill, its speed decreases (less $KE$) while its height increases (more $PE$). Thus, kinetic energy is converted into potential energy.

• Option 1 (Heat to Chemical): Irrelevant to roller coaster energy (no heat - chemical conversion here).
• Option 2 (Chemical to Heat): No chemical reactions occur in the roller coaster's motion to produce heat in this context.
• Option 3 (Potential to Kinetic): This happens when going down the hill (height decreases, speed increases), not at the top.
• Option 4 (Kinetic to Potential): Matches the scenario: as the coaster slows at the top, its kinetic energy (from motion) is converted into potential energy (from height).

Answer:

D. Kinetic energy is changed into potential energy.