Energy is a measure of the ability of an object or a system to do work on another object or system. There are many different types of energy, or forms of energy, that exist in the universe. These are the different ways that an object or a system can possess energy.
The Different Forms of Energy
The most basic and fundamental type of energy is kinetic energy. This is also referred to as the energy of motion. For example, consider a baseball that is flying through the air after being thrown. The ball has kinetic energy because it is in motion. The baseball has energy because it can do work on another object or the ground by hitting it.
In contrast, potential energy is stored energy. Think about a book placed on the edge of a table. The book has potential energy since, if it is pushed off the table, gravity will accelerate the book giving it kinetic energy. The potential energy of the book will be converted into kinetic energy if it leaves the table in this way.
Elastic energy is a type of potential energy that can be stored. One of the key aspects of elastic energy is that the material used to create the energy always returns to its original form. An example of elastic energy is a rubber band. When a rubber band is stretched, energy is created because the bonds of the atoms are strained.
However, when the tension is released, the rubber band returns to its original form. This same example holds true for a gas or liquid and a coiled spring. The bonds of these materials absorb energy as they are stressed and then release that same energy as they are relaxed, returning to their original form.
Thermal energy is, as its name suggests, heat energy. This is in essence a combination of both kinetic and potential energy happening at a microscopic energy.
A hot cup of coffee possesses thermal energy. The molecules of the coffee are in constant motion, vibrating at a pace which cannot be seen by the naked eye. Temperature is actually a measure of how much thermal energy that an object has. The higher the temperature of an object, the faster that the molecules are vibrating and the more thermal energy contained in the object.
Chemical energy is the energy that is released by breaking bonds. When a molecule containing two or more atoms bonded together is broken apart, energy is released by that reaction. One example in the human body is glucose or blood sugar. The body breaks apart a glucose molecule in order to release energy and fuel the body to do work. Chemical energy is an essential part of the body’s daily functions although it can be found throughout the universe.
Electrical energy is another type of energy. All of the matter in the world is made up of atoms. Atoms contain protons with a positive charge, neutrons with a negative charge and electrons which also have a negative charge. The electrons circulate the center of the atom, much like the moon circles around the earth. Electrons can be added or removed from an atom when an electric field is applied. When the electrons are moved, a current of electricity is created which is a form of energy.
Related to electrical energy is electrochemical energy. This is when chemical reactions are used to generate electrical energy. In a process known as electrolysis, electrical energy generated is converted into chemical energy which is then stored. The energy created is often stored in batteries or other fuel-cells created. This dual-energy is created using both electrical and chemical processes.
Electromagnetic energy is most easily though of by considering sunlight. The light that passes from the sun to the earth is actually a form of energy known as electromagnetic radiation. Light is a form of energy that acts as both a particle and a wave and is referred to as a photon. Photons are created when electrons change their orbiting pattern, moving to either a higher or lower level of orbit. Because electromagnetic energy also acts as a wave, it has a wavelength which can either be short or long.
The reason why sunlight may hurt a person’s skin is because it contains photons with very short wavelengths with high frequencies. Radiowaves are another type of electromagnetic energy.
Sound energy is another type of energy that exists in waves. When the head of a drum is hit, the air inside the drum is compressed, giving the air potential energy. Then, the air expands as the drum head returns to its original flat shape and the compressed air expands, turning it into potential energy.
This energy of motion moves and compresses other air, moving down the chain and forming waves which the human ear interprets as sound. Sound waves are an energy of motion that can be created in multiple ways such as a drum being hit, violin string vibrating and many other ways.
Another type of energy is nuclear energy. This is when a reaction that involves changes in the nuclei of atoms releases energy. One example is in the sun where hydrogen nuclei combine together to make helium in a process known as fusion. This combining of nuclei releases energy. One of the most important discoveries in physics, nuclear energy formed the basis of Einstein’s theory of relativity.
These are the most basic and fundamental types of energy sources in the universe today. When considering the basic features of energy, always understand is that energy is the capability of either an object or a system to do work but that capability can present itself in many different ways. Energy can also be converted from one form to another.
In the electrochemical form of energy, energy is created by electricity and then converted and stored as chemical energy. While the form of energy may be changed, it cannot actually be created or destroyed. When considering the different types of energy, remember these basic categories for increased comprehension of how work is performed.