Potential energy is the energy stored in an object due to its position in a force field. It may also be due to the configuration of its parts.
The unit of measure of this form of energy for the International System of Units is the joule (J).
This form of energy is associated with the forces acting on a body. These forces only depends on the position of the body in space. These forces can be represented by a vector at any point in the forming space. This vector is known as a vector force field or force field.
In many cases, the energy an object depends on the position relative to other objects.
Potential energy definition
If a body moves from a starting position to an ending position, work is determined only by these two positions. Therefore, it does not depend on the path of the body but on the result of its position. When this happens, there is a function called potential energy that can be evaluated at both positions to determine work.
This term was introduced by 19th-century Scottish engineer and physicist William Rankine. however, it is related to the Greek philosopher Aristotle's concept of potentiality.
What are the types of potential energy?
The most common types of potential energy are:
Gravitational potential energy depends on the vertical position and the mass of an object. Objects perceive the force of gravity due to a gravitational field. As a result, the object experiments an acceleration due to gravity.
Elastic potential energy of a spring or a plastic element. It is the ability of a body to store energy by stressing its chemical bonds when it is stretched or compressed.
Electric or electrostatic potential energy of a charge in an electric field; an electric charge.
Chemical potential energy. This form of potential energy is based on the energy of the molecules. This stored energy is released or absorbed through chemical reactions.
Examples of potential energy
This type of energy can be transformed into other types such as kinetic energy. Those changes can be easily illustrated by the following example:
By kicking a ball the player transmits energy from his leg to the ball.
This initial energy is converted into elastic potential by deforming the balloon and compressing the air inside it.
This elastic potential energy is converted into kinetic energy the moment the ball leaves at full speed. All elastic energy is energy transformed into kinetic energy.
Let's imagine that the player has kicked the ball with a completely vertical trajectory. As the ball loses speed it will lose kinetic energy, which will be converted into gravitational energy.
When you reach the highest point, the ball will have no kinetic energy, and all of its energy will be potential.
When the ball begins to drop, the gravitational potential energy turns back into kinetic energy.
Another example where you can see this transformation of mechanical energy is a roller coaster. Throughout the journey, the wagon undergoes transformations of kinetic and potential energy. At the highest points, the kinetic energy is minimal and the potential is maximum. At this moment, it is further from the surface of the earth.
At the lowest points, it happens the other way around.