Final answer:
The aluminum can on the high shelf is displaying potential energy because it has an elevated position compared to the floor, which means it has the energy that could be released as kinetic energy if it were to fall.
Step-by-step explanation:
Between an aluminum can on a high shelf and an aluminum can on the floor, the one on the high shelf is displaying potential energy. This is because potential energy is related to the height of an object above a reference level, which is usually taken to be the ground or floor level in many problems. An object gains potential energy when it is lifted to a higher position, as work is done against the force of gravity to raise it. This potential energy is the energy that the object has the potential to release as kinetic energy if it were to fall.
To clarify further with an example, imagine the potential energy of a car parked on the top level of a parking garage compared to the same car on the street. The car at the top has more potential energy due to its elevated position. Similarly, an aluminum can placed on a high shelf has more potential energy compared to one on the floor because of its elevated position. If the can were to fall, the potential energy would be converted into kinetic energy.