Meaning of Energy
What is Energy:
Energy refers to the inherent capacity that bodies have to carry out work, movement or change that leads to the transformation of something.
The word energy is used in different areas such as physics, economics and technology, chemistry, among others, so its meaning is variable, hence energy is related to the ideas of force, storage, movement, transformation or operation.
In a broader sense, the term energy is also used in everyday language to refer to the vigor or activity of a person, object or organization. For example, "Maria woke up with a lot of energy to go to work."
The term energy derives from the Greek energos, which means ‘force of action’ or ‘work force’, and of energetic which means 'activity' or 'operation'.
Energy in physics
In physics, energy is the ability of all bodies to carry out work, action or movement. It is a physical property that is neither created nor destroyed, but is transformed into another type of energy. For example, electrical energy can be transformed into light energy in order to light a light bulb.
In this sense, the law of conservation of energy establishes that the energy that any physical system possesses remains unchanged over time until it is transformed into another type of energy. This is the foundation of the first principle of thermodynamics, a branch of physics that studies the interaction of heat with other types of energy.
The unit of measurement for energy defined by the International System of Units is the joule or joule (J).
Energy in technology and economics
In the area of technology and economics, the term energy refers to the sources of natural resources from which energy can be obtained, transformed and used. These resources are used in various industrial and economic areas to satisfy the production and consumption of goods and services.
In this sense, renewable energy sources can be distinguished such as, for example, wind energy, hydraulic energy, solar energy; and non-renewable energy sources, such as coal, natural gas, oil, atomic energy.
Types of energy
There are two types of energies that are fundamental, which are potential energy and kinetic energy.
Plants transform solar energy into chemical energy through photosynthesis.
Potential energy or storage energy is the energy that a body possesses based on its position or condition with respect to another. This type of energy increases when the bodies that attract each other separate or, conversely, when bodies that repel each other come together. The area where bodies attract or repel each other is called the force field.
Examples of potential energy
- Gravitational energy: when lifting an object from the ground, it separates from the Earth, but the gravitational force field attracts it to its center, hence, when it is released, it falls back to the ground.
- Chemical energy: it is a type of stored potential energy that makes the union between atoms possible and that leads to the transformation of some compounds into others. Exothermic reactions (metabolism) and endothermic reactions (photosynthesis) derive from this type of energy.
- Nuclear energy: it is the potential energy stored in the nucleus of the atom that holds the subatomic particles together, but that when reacting transforms one atom into a different one. Nuclear energy can be obtained by nuclear fusion or nuclear fission, and it can be used to obtain electrical energy, among others.
See also Nuclear fission
Vehicles move through the transformation of thermal energy into kinetic energy.
Kinetic energy is the energy generated by the movement of a body, and which in turn is affected by its mass and speed. It is a type of energy that takes great advantage of natural resources, for example, hydraulic energy is generated from water to obtain electricity.
Examples of kinetic energy
- Thermal energy: it has to do with the degrees of heat and the temperature of a body as its internal particles move, therefore, if there is a lot of movement, the greater the thermal energy will be.
- Automobile movement: the thermal energy generated by fossil fuels is used to transform it into kinetic energy, which will allow the vehicle's engine to work and move.
- Roller coaster: when the roller coaster cart begins its descent, it gains speed, due to its weight and mass, until it reaches its maximum speed until it reaches a lane ascent again.
Natural energy sources
Turbine from which wind energy can be obtained through the wind.
Natural energy sources are those extracted through renewable or non-renewable resources, that is, energies obtained through elements in nature. Some examples are:
- Solar energy: it is that which is obtained from the radiation of the Sun on the Earth, and which goes through a process of transformation into electrical energy for its use. It is a clean and renewable energy.
- Wind energy: it is the energy obtained from the wind that produces electricity.
- Hydraulic energy: is that obtained through the force of falling bodies of water. Also called hydropower or hydropower, the potential energy of waterfalls is transformed into electricity through turbines.
- Geothermal energy: it is that which is extracted from the internal heat of the Earth, from the subsoils. It is considered one of the cleanest renewable energies, since it has a minimum environmental and landscape impact.