There is no exact definition for energy, but we can say that it is associated with the capacity to produce action and/or movement and manifests itself in many different ways, such as movement of bodies, heat, electricity, etc.
According to the Lavoisier's Principle, a energy it cannot arise from nothing and it cannot be destroyed. The only possibility that exists is the transformation of one type of energy into another, such as energy from a waterfall in hydroelectric plants that is converted into electrical energy.
Renewable and non-renewable energy
The types of energy coming from finite sources (energy sources that will have an end) are called non-renewable energies. This is the case of energy generated from fossil fuels such as oil and coal. The energy generated from sources that have natural replacement capacity are called renewable or clean energy. This is the case of energy from sunlight and energy from the force of winds (wind energy).
Main forms of energy
Kinetic energy: It is the energy associated with the movement of bodies. The greater the speed at which a body moves, the greater its kinetic energy.
The equation below mathematically defines the kinetic energy. In the equation, m is the mass of the element that moves and v is your speed.
Ec = mv2
2
Potential energy: The energy stored due to the position of a body in relation to the surface is called gravitational potential energy. The higher an object is in relation to the ground, the greater its speed when reaching the ground if it starts a fall. Mathematically, gravitational potential energy is given by the product of the body's mass, height and gravity.
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Epg = m.g.h
When the potential energy is associated with the deformation of an elastic material, it will be called elastic potential energy, and its calculation will depend on the deformation (x) caused in the material and a constant (k) that determines the elasticity of the material.
Epe = k.x2
2
Thermal energy (Heat): O heat is the thermal energy associated with the kinetic energy of the molecules that make up an element. The manifestation of heat will only occur if there is a difference in temperature between two bodies.
Chemical energy: It is the energy released or formed from chemical reactions, as the energy produced by cells and batteries.
Solar energy: It is energy from sunlight. This form of energy can be used in the generation of electrical energy through photovoltaic panels, for example.
Wind energy: It is the energy that comes from the movement of air masses. The force of the winds can be used to turn propellers and turbines in the production of electrical energy.
Nuclear energy:It is the energy obtained from the phenomenon of nuclear fission, in which the nucleus of an atom splits, generating the release of a large amount of energy.
By Joab Silas
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
JUNIOR, Joab Silas da Silva. "What is energy?"; Brazil School. Available in: https://brasilescola.uol.com.br/o-que-e/fisica/o-que-e-energia.htm. Accessed on June 27, 2021.
