Potential energy is a concept which can be more simply understood as “stored energy.” It is energy stored within a physical system, usually as a result of an object’s position. Potential energy examples include those to do with gravity, elasticity, chemistry, electricity and thermal energy.
One way of explaining energy is that it always falls into one of two forms: potential and kinetic. Some scientists object to this explanation as too simplified or artificial, but it is useful for explaining some general principles. Kinetic energy is that related to movement. Potential energy is that stored within a stationary object. Understanding this can explain how energy continues to exist even when its effects can’t be seen.
One of the easiest potential energy examples to understand is elastic potential energy. This can be illustrated by drawing back a bow. Because the shape of the string of the bow is temporarily deformed, when it is released it will attempt to return to its original shape, thus producing the energy which propels the arrow. Until the bow is released, this energy exists as elastic potential energy.
Another of the common potential energy examples is gravitational energy. A falling object will accelerate thanks to kinetic energy. When the object hits the ground, this same amount of energy will be released as heat and sound in the collision. However, before the object falls, this amount of energy is stored as potential energy.
The amount of gravitational energy will depend on both the mass of the object and the height at which it is resting. If you move a book from one shelf to a higher shelf, the book’s potential energy will increase. It may seem confusing that the same book can increase its potential energy without any physical changes. However, the increase in potential energy will come from and equal the energy you expend in lifting the book higher up.
Chemical potential energy exists in the way atoms or molecules are formed. This energy is then released and transformed when the substance is involved in a chemical reaction. For example, when a fuel is burned, its chemical potential energy is converted to heat.
Electrical potential energy comes in several forms. An electrically charged object at rest has potential energy which relates to other nearby objects which are also electrically charged. A variation of this is for charged objects which aren’t at rest; in this situation there is magnetic potential energy. Of all the potential energy examples, perhaps the most spectacular is through electrically charged particles inside an atomic nucleus, which hold nuclear potential energy.