Question

________ energy is the energy of the motion or vibration of molecules in a substance.

Answer 1

Heat energy is the energy of the motion or vibration of molecules in a substance. The answer is letter A. A wrecking ball on its way down before it hits a building is an example of kinetic energy being converted into mechanical energy. The answer is letter D.

Answer 2

The answer to the first question is A. Heat, because in order to heat up or catch fire, the molecules have to vibrate quickly.

This wrecking ball is an example of potential energy being converted into kinetic energy, so your answer is B. potential, kinetic.

Source: I have had to answer both questions before.