Potential Energies

Potential Energies

An object that is higher up can fall. This shows that it has some kind of energy that we cannot see. We call this kind of energy "potential energy." In this case, this is due to gravity, so it is also called gravitational potential energy.

When rain clouds move against each other, they accumulate electrical charges. They can reach a voltage so high that they overcome the resistance in the air between clouds and ground. Then electric current can flow through the sky, producing lightning that we see. The energy stored between clouds and ground is electrical in nature. We call this electrical potential energy.

If we stretch a rubber band, there is also energy hidden in it. When you hook one end of the band over a stone and let go, the stone flies a long way. (Be careful not to hit someone.) Since this energy is due to the elastic nature of the rubber band, it is called elastic potential energy.

Other examples are energy stored in food and batteries. This is chemical potential energy.

The Physics Notes