Potential and kinetic energy are the two main types of energy. Learn about potential energy, including its definition, units, examples, formulas, and how to calculate it.
What Is Potential Energy?
Potential energy is stored energy. The energy comes from an object’s relative position, its electric charge, internal stresses, or other factors.
Because potential energy comes in many forms, it is further classified as elastic potential energy, chemical potential energy, nuclear potential energy, electric potential energy, gravitational potential energy, or magnetic potential energy.
In formulas, potential energy is PE, U, or V. Potential energy depends on the observer’s frame of reference, so it is not invariant.
Potential energy does not depend on the path taken between maximum and minimum points. For example, you achieve the same potential energy if you hike a winding trail to the top of a mountain or if you get pulled straight up.
Potential Energy Examples
There are many examples of potential energy in the everyday world. Remember, potential energy depends on relative position of objects, so you can’t just say “a ball has potential energy.” It has potential energy when a force can act upon it.
So, raising a ball gives it energy due to the force of gravity. If the ball is an electron, it has potential energy when distanced from another charge due to the attractive and repulsive forces of protons and other electrons.
- A raised object, such as a book, weight, or apple
- A person at the top of a diving board
- An object at the top of a hill
- A stretched spring or rubber band
- A drawn bow
- Water at the top of a waterfall
- Water behind a dam
- A charged battery
- An explosive
- A chemical bond before it is broken
- Firewood, gasoline, and other fuels
- Food before you digest it
- A chemical hot pack or cold pack before you activate it
- A plugged-in appliance before you turn it on
- Two magnets held apart from each other
- An unstable atom before it decays or undergoes fission
- A hanging pendulum at its highest point
- A stretched rubber band on a toy airplane
- A coiled spring in a wind-up toy
- A compressed spring in a car suspension system
- A person holding a stretched slingshot
- A compressed air tank
- A skier at the top of a slope
- A gymnast at the top of a vault
- A roller coaster at the top of the track
- A raised flag on a flagpole
- A person lifting a barbell in the gym
- A bungee jumper at the top of the jump
- A rock balanced on the edge of a cliff
- A person standing on a ladder
- A raised drawbridge
- A raised elevator
- A crane with a load in the raised position
- A person on a swing at its highest point
- A compressed gas cylinder
- A compressed spring in a mousetrap
- A person on a trampoline at the highest point of a bounce
- A compressed accordion-style camera shutter
- A raised garage door
- A compressed air rifle
- A person holding a pulled-back bow and arrow
- A raised drawstring on a window blind
- A stretched elastic headband
- A raised basketball on a hoop
- A compressed diving board
- A person at the top of a ladder
- A raised seesaw with a person on one end
- A compressed accordion-style folding chair
- A raised plank on a seesaw
- A compressed air mattress
- A person on a swing at the highest point
- A raised part of a seesaw with a person on the other end
- A raised rowing machine handle
- A compressed jack-in-the-box
- A raised bicycle pedal
- A stretched wire on a musical instrument
- A raised escalator step
- A person holding a stretched jump rope
- A compressed spring-loaded doorstop
- A stretched elastic band on a model airplane
- A raised end of a seesaw with a person on the other end
- A compressed button on a retractable ballpoint pen
- A person holding a stretched resistance band
- A compressed gas lighter
- A raised part of a lever with a person on the other end
- A stretched wire on a harp
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
Example of 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
Example of 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