Item RG161002: Both a falling rock and a rock on a cliff have energy because all things have energy.

The figure below shows two identical rocks. The rock on the left is falling, while the rock on the right is sitting on a cliff.

Does either rock have energy?

  1. The falling rock has energy because it is moving, and things that move have energy. The rock on the cliff does not have energy because it is not moving.
  2. The rock on the cliff has energy because it has energy stored inside of it. The falling rock does not have energy because it gave off its energy when it started to fall.
  3. Neither rock has energy because rocks are not alive, and only living things have energy.
  4. Both rocks have energy because all things have energy.