Energy is the ability of bodies to do work and cause changes in themselves or in other bodies. In other words, the concept of energy is defined as the ability to make things work.
The unit of measurement we use to quantify energy is the joule (J) , after the English physicist James Prescott Joule.
7 Forms of energy
Energy manifests itself in different ways, thus receiving different names depending on the actions and changes it can cause.
Mechanical energy is that related to both the position and the movement of bodies and, therefore, involves the different energies that a moving target has, such as kinetic and potential energy.
The potential energy refers to the position occupied by a mass in space.
The kinetic energy on the other hand is manifested when the bodies move and is associated with speed .
Internal energy manifests itself from temperature. The hotter a body is, the more internal energy it will have.
When two points have a potential difference and are connected through an electrical conductor, what we know as electrical energy is generated, related to electrical current.
It is associated with the amount of energy that passes from a hot body to a colder one manifesting itself through heat.
This energy is attributed to the presence of an electromagnetic field, generated from the movement of electric and magnetic particles moving and oscillating at the same time. They are what we know as electromagnetic waves, which propagate through space and move at the speed of light.
The Sun is an example of electromagnetic waves that can manifest as light, infrared radiation, and also radio waves.
Chemical energy is manifested in certain chemical reactions in which chemical bonds are formed or broken. Coal, natural gas or the operation of batteries are some examples of the use of this energy.
The nuclear energy
Nuclear energy is generated to the atoms interact with each other. It can be released through its break, which is known as fission, or its union, which is called fusion.
Properties of energy
Energy has 4 basic properties:
- Becomes. Energy is not created, but is transformed, and it is during this transformation that different forms of energy manifest.
- Is preserved. At the end of any energy transformation process there can never be more or less energy than there was at the beginning, it always remains. Energy is not destroyed .
- Is transfered. Energy passes from one body to another in the form of heat, waves, or work.
- Degrades. Only part of the transformed energy is capable of producing work and the other is lost in the form of heat or noise (unwanted mechanical vibrations).
There are three main ways to transfer energy from one body to another:
When a job is done, energy is passed to a body that changes from one position to another. As it happens, for example, if we push a box to move it: we are doing a job so that its position varies.
Waves are the propagation of disturbances of certain characteristics, such as the electric field, magnetism, or pressure. As they move through space they transmit energy.
It is a type of energy that manifests itself when energy is transferred from a hot body to a colder body. This energy can travel in three main ways:
- Conduction : When one end of a material is heated, its particles vibrate and collide with neighboring particles, transmitting part of its energy to them.
- Radiation: Heat propagates through waves of infrared radiation (waves that propagate through vacuum and at the speed of light).
- Convection: which is typical of fluids (liquid or gaseous) in motion.