The cart has no mechanical energy. The cart's mechanical energy is all kinetic. The cart's mechanical energy is all potential. The cart's mechanical energy is half potential and half kinetic.
I gave my students this multiple choice question: Which of the following describes the mechanical energy of a cart at rest at the top of a steep hill?

Only one answer is correct among these 4 choices:
- The cart has no mechanical energy.
- The cart's mechanical energy is all kinetic.
- The cart's mechanical energy is all potential.
- The cart's mechanical energy is half potential and half kinetic.

Could you tell me which one is correct?

The cart's mechanical energy is all potential.