In this lesson, you will learn about the different kinds of energy and how these types of energy can be transformed from one form to another. You will also learn about some uses of these energy transformations in everyday life.
What is Energy Transformation?
The conservation of energy principle states that energy can neither be destroyed nor created. Instead, energy just transforms from one form into another. So what exactly is energy transformation? Well, as you might guess, energy transformation is defined as the process of changing energy from one form to another.
There are so many different kinds of energy that can transform from one form to another. There is energy from chemical reactions called chemical energy, energy from thermal processes called heat energy, and energy from charged particles called electrical energy. The processes of fission, which is splitting atoms, and fusion, which is combining atoms, give us another type of energy called nuclear energy. And finally, the energy of motion, kinetic energy, and the energy associated with position, potential energy, are collectively called mechanical energy.
That sounds like quite a lot, doesn’t it? Well it is, but don’t worry, it’s actually all pretty easy to remember. Next, we’ll explore all of these kinds of possible transformations in more detail.
Different Types of Energy Transformations
Chemical energy is the energy stored within a substance through the bonds of chemical compounds. The energy stored in these chemical bonds can be released and transformed during any type of chemical reaction.
Think of when you’re hungry. When you eat a piece of bread to satisfy this hunger, your body breaks down the chemical bonds of the bread and uses it to supply energy to your body. In this process, the chemical energy is transformed into mechanical energy, which you use to move, and which we’ll cover in more detail in a moment. It also transforms it into thermal energy, which is created through the metabolic processes in your body to generate heat. Most of the time, chemical energy is released in the form of heat, and this transformation from chemical energy to heat, or thermal energy, is called an exothermic reaction.
Next, there are two main types of mechanical energy: kinetic energy and potential energy. Kinetic energy is the energy associated with the motion of an object. Therefore, any object that moves has kinetic energy. Likewise, there are two types of potential energy: gravitational potential energy and elastic potential energy. Gravitational potential energy is associated with the energy stored by an object because of its location above the ground. Elastic potential energy is the energy stored by any object that can stretch or compress. Potential energy can be converted to kinetic energy and vice versa.
For example, when you do a death-defying bungee jump off of a bridge, you are executing a variety of energy transformations. First, as you prepare to jump, you have gravitational potential energy – the bungee cord is slack so there is no elastic potential energy. Once you jump, you convert this gravitational potential energy into kinetic energy as you fall down. At the same time, the bungee cord begins to stretch out. As the cord stretches, it begins to store elastic potential energy. You stop at the very bottom when the cord is fully stretched out, so at this point, you have elastic potential energy. The cord then whips you back up, thereby converting the stored elastic potential energy into kinetic energy and gravitational potential energy. The process then repeats.
Electrical energy is the energy carried by charged particles as they move around a conductor. A perfect example of electrical energy being released is during a lightning storm. A lightning strike on a tree is an example of electrical energy being transformed into heat or thermal energy. The tree becomes hot and may even burn as a result of the electrical discharge.
Chemical energy can also be converted into electrical energy. For example, the chemical energy in a battery is converted into electrical energy. The electrical energy, which involves the motion of electrical charges or currents, can be used to power everyday devices like computers and flashlights.
Mechanical energy can also be transformed into electrical energy. For example, a hydroelectric plant uses the mechanical energy of flowing water to generate electrical energy. Wind energy is another mechanical to electrical energy transformation. The mechanical energy of the wind is transformed into electrical energy which can then be transformed into other types of energy.
Finally, nuclear energy is the energy stored in the nucleus of an atom. This energy can be manifested in two different ways. First is the fission process. In nuclear fission, an unstable nucleus breaks apart and, in the process, releases a tremendous amount of energy. The atomic bomb is an example of a fission process. In short, the energy released from breaking a tiny atomic nucleus can release enough energy to destroy a city or two. The energy from nuclear fission can be converted into electrical energy, thermal energy, and mechanical energy.
The other nuclear energy process is actually the opposite of fission. Nuclear fusion is the process of fusing two different nuclei to create another larger nucleus. This process also releases a tremendous amount of energy. Of the two types of nuclear energy, fusion is the most desirable because of the lack of nuclear waste. Fission processes leave residual effects like radiation, while fusion does not. Currently, we only have fission nuclear power plants, but research toward harnessing the power of nuclear fusion is underway.
There are other secondary types of energy but these are just variations of the energy described above. For example, radiant energy and solar energy are results of electrical energy and nuclear energy. The sun releases energy by the process of fusion, combining hydrogen atoms to make helium atoms. The result is a release of light energy and solar energy which is also called electromagnetic radiation. Another type of energy is sound energy. Sound energy is the energy carried by sound waves. However, the sound has to be created by a mechanical or an electrical process, so we can classify this as a mechanical or electrical type of energy.
As you can see, most types of energy can be transformed into other types of energy. That is the basic concept behind energy transformations. The odd thing is that thermal energy is usually the end product of a transformation rather than the cause of a transformation. Most energy transformation processes end in the production of thermal energy. That being said, the one main example of thermal energy being transformed into another type of energy is an engine. The temperature difference in an engine is what allows the engine to operate and produce mechanical energy that moves the automobile. However, this process also produces thermal energy as a by-product.
The energy conservation principle states that energy can neither be destroyed nor created. Rather, energy will transform from one form to another. Many of these energy transformations can be useful. For instance, converting mechanical energy from a waterfall into electrical energy or converting nuclear energy to electrical energy to power a city is very useful. Some of these can be harmful, however, such as releasing nuclear energy to destroy a small city. But the main takeaway from this lesson is that for any type of process you can think of, there is probably an energy transformation involved. Try to think of everyday processes and look for energy transformations in them.
Use what you learned during this lesson to accomplish these goals:
- State the energy conservation principle
- List several forms of energy that are capable of transformations
- Discuss various types of energy transformations
- Cite examples of energy transformations that are either useful or harmful