There are various forms or types of energy and they are all interchangeable.
Everything has energy. From stones to water to humans to chemicals, they all contain a form of energy within. There are many different types and this article will hopefully explain the main types and also some fundamental facts about energy.
Kinetic Energy; An object has kinetic energy if it is moving. For example a car has kinetic energy when it is moving and a circular saw also has kinetic energy as it is spinning, the motion does not necessarily need to be transitional, it can also be rotational such as in this case. In fact everything has some form of kinetic energy as the molecules it is made up of vibrate thus it has some “hidden” kinetic energy, unless of course it is at absolute zero where nothing moved.
Potential Energy; There are a few types of potential energy the main ones being: Gravitational potential energy, and object has this when it is raised up a height and gravity could bring it back to solid ground. When something is higher it has more gravitational potential energy. Chemical potential energy: like that stored in a battery. Elastic potential energy: like that stored in a spring or some elastic, or anything that will cause an opposite force when stretched.
Electrical Energy; The flow of negatively charged electrons that cause work to be done on something else such as a bulb or motor.
Waves; Waves such as microwaves, light rays or x-rays are streams of photons which are little packets or energy. The higher up the spectrum of electromagnetic waves the greater the energy. For example, gamma rays contain the most energy and radio waves contain the least.
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All these types of energies are interchangeable and be converted into each other. A good example is the chemical energy in a battery being used to run a motor creating kinetic energy to lift a box giving it gravitational potential energy, or kinetic energy being used to run a generator creating electric energy. A rollercoaster has many energy changes thoughout, try to think of how many conversions of energies into different types you can think of!
The one fundamental principle about energy is that it can neither be created nor destroyed, merely converted into other types of energy. This is known as the conservation of energy and is at the heart of all modern physics.