What is an example of potential energy?

Potential energy is stored energy from an object. Instead of coming from motion, it can come from its position relative to others, internal stress, electric charge, or its condition. This object has the capability of producing energy as these conditions change. This energy could be mechanical energy, chemical energy, electric energy, nuclear energy, or magnetic energy.

Índice Show

Mechanical Potential Energy
Examples of Gravitational Potential Energy
Examples of Elastic Potential Energy
Chemical Potential Energy
Electric Potential Energy
Other Forms of Potential Energy
Nuclear Potential Energy
Magnetic Potential Energy
Potential Energy and Kinetic Energy
Gravitational Potential Energy
Elastic Potential Energy
Check Your Understanding
What is a potential energy and 5 examples?
What are 3 examples of potential energy at home?
What are 4 types of potential energy and examples?
Which is the best example of potential energy?

Boy archer with bow and arrow

Mechanical Potential Energy

Mechanical energy is the energy of movement. All items have potential energy based on their position (gravitational potential energy) and ability to bounce (elastic potential energy). When the potential energy of an object is combined with its kinetic energy, it results in mechanical energy.

Examples of Gravitational Potential Energy

When something has a high position, its gravitational potential energy is high. For example, a book on a high bookshelf has higher potential energy than a book on the bottom shelf because it has farther to fall. Other examples of items with gravitational potential energy include:

A raised weight
Water that is behind a dam
A car that is parked at the top of a hill
A yoyo before it is released
River water at the top of a waterfall
A book on a table before it falls
A child at the top of a slide
Ripe fruit before it falls

Examples of Elastic Potential Energy

The material an item is made of can affect its potential energy as well. An elastic ball has higher elasticity than a bowling ball; therefore, it will bounce higher with the same amount of force. Here are some more examples of items with elastic potential energy.

A coiled spring
An archer's bow with the string pulled back
A stretched rubber band
Soccer balls before players kick them
A diving board just before someone dives

If you’d like examples of kinetic mechanical energy, check out this helpful list of everyday items that use mechanical energy.

Chemical Potential Energy

Chemical energy occurs when energy is released during a chemical reaction. Potential chemical energy is the energy stored in the bonds of these chemicals, ready to react with another chemical. Some examples include:

A charged battery
Explosives
Green leaves before the sun shines on them (potential photosynthesis)
Gasoline before it is ignited
Fireworks before they are launched
Wood in a fireplace before it burns
Iron before it gets wet and rusts
Fruit juice before it ferments
The wick in a candle

Looking for more examples of chemical energy? Check out an article that details nine ways you might see chemical energy in daily life.

Electric Potential Energy

When you see a light switch that’s off, you can’t see the charge that’s waiting to flow through the wires. That’s just one example of electric potential energy. Additional examples include:

An incandescent light bulb that is turned off
Your car's headlights before they are turned on
A radio tower that is not working
A cell phone that is turned off
Solar cells at night
A black light turned off
A television before it is turned on

For more examples of electric energy in action, read an article about household items that use electric energy.

Other Forms of Potential Energy

Nuclear Potential Energy

Nuclear potential energy is stored in the particles of an atom. When the atom is split (in nuclear fission) or atoms are combined (in nuclear fusion), the energy released becomes kinetic energy. Learn more about the uses of nuclear energy.

Magnetic Potential Energy

Like gravitational potential energy, magnetic potential energy affects how items work based on their position. Items with high magnetic potential energy, such as metal spoons or ball bearings, respond strongly to a magnetic force. Objects with lower magnetic potential energy, such as a plastic spoon or a rubber ball, are not as affected by a magnetic pull.

Potential Energy and Kinetic Energy

The laws of physics mandate that almost every item has some kind of potential energy. When force is applied to the object, it converts to kinetic energy.

Our helpful article explains how kinetic energy appears in the world around us.

An object can store energy as the result of its position. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy of position is referred to as potential energy. Similarly, a drawn bow is able to store energy as the result of its position. When assuming its usual position (i.e., when not drawn), there is no energy stored in the bow. Yet when its position is altered from its usual equilibrium position, the bow is able to store energy by virtue of its position. This stored energy of position is referred to as potential energy. Potential energy is the stored energy of position possessed by an object.

Gravitational Potential Energy

The two examples above illustrate the two forms of potential energy to be discussed in this course - gravitational potential energy and elastic potential energy.

Gravitational potential energy is the energy stored in an object as the result of its vertical position or height. The energy is stored as the result of the gravitational attraction of the Earth for the object. The gravitational potential energy of the massive ball of a demolition machine is dependent on two variables - the mass of the ball and the height to which it is raised. There is a direct relation between gravitational potential energy and the mass of an object. More massive objects have greater gravitational potential energy. There is also a direct relation between gravitational potential energy and the height of an object. The higher that an object is elevated, the greater the gravitational potential energy. These relationships are expressed by the following equation:

PEgrav = mass • g • height
PEgrav = m *• g • h

In the above equation, m represents the mass of the object, h represents the height of the object and g represents the gravitational field strength (9.8 N/kg on Earth) - sometimes referred to as the acceleration of gravity.

To determine the gravitational potential energy of an object, a zero height position must

first be arbitrarily assigned. Typically, the ground is considered to be a position of zero height. But this is merely an arbitrarily assigned position that most people agree upon. Since many of our labs are done on tabletops, it is often customary to assign the tabletop to be the zero height position. Again this is merely arbitrary. If the tabletop is the zero position, then the potential energy of an object is based upon its height relative to the tabletop. For example, a pendulum bob swinging to and from above the tabletop has a potential energy that can be measured based on its height above the tabletop. By measuring the mass of the bob and the height of the bob above the tabletop, the potential energy of the bob can be determined.

Since the gravitational potential energy of an object is directly proportional to its height above the zero position, a doubling of the height will result in a doubling of the gravitational potential energy. A tripling of the height will result in a tripling of the gravitational potential energy.

Use this principle to determine the blanks in the following diagram. Knowing that the potential energy at the top of the tall platform is 50 J, what is the potential energy at the other positions shown on the stair steps and the incline?

Elastic Potential Energy

The second form of potential energy that we will discuss is elastic potential energy. Elastic potential energy is the energy stored in elastic materials as the result of their stretching or compressing. Elastic potential energy can be stored in rubber bands, bungee chords, trampolines, springs, an arrow drawn into a bow, etc. The amount of elastic potential energy stored in such a device is related to the amount of stretch of the device - the more stretch, the more stored energy.

Springs are a special instance of a device that can store elastic potential energy due to either compression or stretching. A force is required to compress a spring; the more compression there is, the more force that is required to compress it further. For certain springs, the amount of force is directly proportional to the amount of stretch or compression (x); the constant of proportionality is known as the spring constant (k).

Fspring = k • x

Such springs are said to follow Hooke's Law. If a spring is not stretched or compressed, then there is no elastic potential energy stored in it. The spring is said to be at its equilibrium position. The equilibrium position is the position that the spring naturally assumes when there is no force applied to it. In terms of potential energy, the equilibrium position could be called the zero-potential energy position. There is a special equation for springs that relates the amount of elastic potential energy to the amount of stretch (or compression) and the spring constant. The equation is

PEspring = 0.5 • k • x2
where k = spring constant
x = amount of compression
(relative to equilibrium position)

To summarize, potential energy is the energy that is stored in an object due to its position relative to some zero position. An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height. An object possesses elastic potential energy if it is at a position on an elastic medium other than the equilibrium position.

Check Your Understanding

Check your understanding of the concept of potential energy by answering the following questions. When finished, click the button to view the answers.

1. A cart is loaded with a brick and pulled at constant speed along an inclined plane to the height of a seat-top. If the mass of the loaded cart is 3.0 kg and the height of the seat top is 0.45 meters, then what is the potential energy of the loaded cart at the height of the seat-top?

2. If a force of 14.7 N is used to drag the loaded cart (from previous question) along the incline for a distance of 0.90 meters, then how much work is done on the loaded cart?

Note that the work done to lift the loaded cart up the inclined plane at constant speed is equal to the potential energy change of the cart. This is not coincidental! The reason for the relation between the potential energy change of the cart and the work done upon it is the subject of Lesson 2.

What is a potential energy and 5 examples?

Stones sitting on an edge of a cliff possess potential energy. The potential energy will be converted if the stones fall to kinetic energy. Tree branches high up the tree have potential energy because they can fall to the ground. The food that we eat has chemical potential energy.