Didactic Encyclopedia

Custom Search

# What is the meaning of Energy? Concept, Definition of Energy

## What is: "energy" ‒Definiciones and concepts -

### 1. Concept of energy in the Wikipedia Encyclopedia

The term energy (Greek ἐνέργεια/energeia, activity, operation; ἐνεργoς/energos = force of action or force working) has different meanings and definitions, related to the idea of a capacity to act, to convert or to set in motion.
In physics, 'energy' is defined as the ability to perform a job. In technology and economy, 'energy' refers to a resource (including its associated technology) to extract it, transform it, and give it an economic or industrial use.

### The concept of energy in physics

#### Classical mechanics

In classical physics, the universal law of conservation of energy - which is the basis of the first law of thermodynamics-, indicates that energy linked to an isolated system remains constant in time. This means that for a multitude of classical physical systems the amount of mechanical energy, heat energy, electromagnetic energy, and other types of potential energy is a constant number. For example, the kinetic energy is quantified based on the movement of matter, the energy potential according to properties such as the State of deformation or to the position of the matter in relation to the forces acting on it, heat energy according to the thermodynamic State, and chemical energy according to the chemical composition.

#### Quantum mechanics

However, keep in mind that according to the theory of relativity not defined according to the classical mechanical energy remains constant, but that what is preserved is the equivalent masa-energia. I.e., the theory of special relativity establishes equivalence between mass and energy by which all bodies, by being formed from matter, possess an equivalent additional energy, and considering the principle of conservation of energy this energy should be taken into account to obtain a conservation law (naturally on the other hand the mass is not conserved in relativity(, but that the only possibility for a conservation law is counted together the energy associated with the mass and all other forms of energy).

#### Its mathematical expression

Energy is a property of physical systems, is not a real physical condition, or an "intangible substance". In classical mechanics, is represented as a magnitude scale. Energy is a mathematical abstraction of a property of physical systems. For example, is that a system with zero kinetic energy is at rest. In relativistic problems the energy of a particle does not can be represented by a scalar invariant, but by the temporal component of a cuadrivector energy-momentum (cuadrimomento), since different observers do not measure the same energy if they do not move at the same speed with respect to the particle. Considering continuous distributions of matter, the description becomes still more complicated and the correct description of the amount of movement and energy requires the use of the tensor boosting.
Used as an abstraction of the physical systems the ease to work with magnitudes scalar, in comparison with the vector like velocity or acceleration magnitudes. For example, in mechanics, is can fully describe the dynamics of a system kinetic, potential, depending on energies that make up the mechanical energy, which in Newtonian mechanics has the property preserved, i.e. to be invariant over time.
Mathematically, the conservation of energy for a system is a direct consequence that the equations of evolution of that system must be independent of the instant of time considered, in accordance with the Noether theorem.

### 2 Concept of energy

Word that comes from the latin power and force of will, strength and tenacity in the activity concerned. Abstract concept considered as cause and other observable phenomena which are nothing more than different manifestations of it. The concept of energy is equivalent to the working.
In economics, the concept is used to refer to the fundamental economic magnitude, in that it admits that there is a relationship between the basic elements of the social status of a human group and the shape or the amount of energy which can have.
On the other hand, in the Aristotelian philosophy, power was considered in a passive sense: the current time of the substance, in opposition to the possible reality. Modern philosophy, based on the significance given by physics, especially by thermodynamics, conceived the energy in a sense activist, as a common measure corresponding to the different forms of movement of matter.
Psychoanalytic theory considers the transformable mental energy and proceeding, in its performance, in a way analogous to the physical energy. As electricity can be transformed into light or energy thermal or dynamic; You can say in psychoanalytic terms which the psychic power is a transformation of the somatic.
Other beliefs (such as the occult) believe that energy is the force that acts both in the material and the immaterial. We could not exist without this principle. The world is composed of constant energy vibrating at different scales of frequency, which makes that its manifestations are multiple.
Energy multiplies with ratio first force that moves eses, field energy, and that energy decreases in relation to the first force wear. Thus the human dies in physical scale when wears his physical energy, but it still exists in other intangible energy fields.

### 3. Definition of energy

Power is the ability to produce any type of work or put something in motion. Although the term can be defined from a wide variety of approaches, the truth is that all of them bear some kind of relationship with the definition provided. Energy is a topic of enormous relevance for human activity, insofar as it allows the development of life on Earth and sustains economic activity.
The energy source more important for man is the Sun. So thanks to the sunlight that vegetables can, through specially designed cells for that task, take energy and produce their own food which leads to the production of oxygen. So in view of the facts, vegetables also are the first source of energy of the food chain, where they serve to nourish the herbivores, and from there, to the rest of living beings, including the scavengers. Indeed, the energy provided by the Sun in the form of light (photons or light energy) is converted by plants into chemical energy stored in nutrients. This energy is released as heat energy by animals.
It is worth to point out that, for the activities of production of goods and services is also important sources of energy requirement. Therefore, that the exploitation of energy resources has enormous strategic importance, because it is the basis on which is run across the economy. The main sources of energy in this respect constitute what hydrocarbons, which are compound organic that comply by hydrogen and carbon; Thus, oil and natural gas are indispensable for human activity unfolds in our days. It is interesting to note that these products have originated from a slow and progressive process which took as a starting point to living beings, reason by which they are known as "fossil fuels". In strict terms and recalling the previous paragraph, the energy contained in these products nonetheless be also originated in the Sun, although thousands of years ago.
One of the main problems currently awaiting its solution is the need to extract energy from new sources. Nuclear power offered a possible answer for a long time, but their cost and hazardous accidents associated with it acted to the detriment of this possibility. Other variants to generate power may be the use of wind, tides, the heat of the Earth, of the rivers, etc. In the particular case of propulsion by air in motion, known as wind power, is known since long ago in the framework of the use of mills for the most varied purposes. Currently, it is possible to obtain large aliquots of energy with this resource, although it is limited to windy areas. On the other hand, the movement of water (either by means of the tides or the activity of the rivers) represents a resource of great interest for its cleanliness and its ecological feature, although you can depend greatly on climatic factors and the flow of the rivers involved in the process. The use of solar cells to accumulate energy from the photons from the Sun directly is a remarkable possibility, but admits that a large number of cells is required to achieve this effect even for small consumers. Finally, some alternative ways, such as (obtained from scrap wood) wood energy, geothermal energy (from the heat of the Earth) and bioenergy (such as the gas produced by certain strains of bacteria) are a door of hope for the generation of energy. New possibilities with regard to this issue will be evaluated in the future.

### 4. Definition of energy

In latin is where find us the etymology of the word energy. We have more exactly in the term energīa, which in turn, as you found, comes from the Greek word ένέρϒεια.
The concept of energy is related to the ability to generate movement or achieve the transformation of something. In the economic and technological fields, the energy makes reference to a natural resource and the associated elements which allow to make industrial use of the same.
For example: 'the country has serious problems of energy by lack of investment, ' "Gomez is a player of high-energy, able to change the appearance to the team," "In the last week, already has been cut power three times".
For physics, energy is an abstract magnitude which is linked to the dynamic state of a closed system, and that remains unchanged over time. It is an abstraction that is assigned to the State of a physical system. Due to various properties (chemical composition, mass, temperature, etc.), all bodies have energy.
This field, the physics, which leads us to determine in the same occurs with the mention of various types of energy. In particular, we will have to cope with two: the quantum and the classical.
Different types of energy according to the field of study can be detailed. Mechanical energy, for example, is the combination of the kinetic energy (which generated from motion) and potential energy (linked to the position of a body within a field of forces).
Understood as a natural resource, energy is not a good in itself, but is that a good qualified as an intermediate, since it enables the satisfaction of certain requirements when there is a good or a service you offer.
Energy can also be classified according to source. Non-renewable energy is called that comes from exhaustible sources, such as from oil, coal or natural gas. On the other hand, renewable energy is virtually infinite, and solar and wind energy (generated by the action of the wind).
Today day precisely, before the awareness that, little by little, are taking the society of the essential that is that we embark the protection of the environment, is occurring a mentioned renewable energy boom. And it is that the use of them contributes to that I let exploit other sources that pollute, that they hurt greatly to the natural surroundings, and consequently also to us and to our own well-being.
The basis of the use of these renewable mentioned is that you opt for an energy that takes advantage of inexhaustible natural sources, as it would be the case in the light of the Sun. In the same way also advocates an energy that is capable of regenerating naturally and which, therefore, does not cause any damage to the natural environment.
Thus, for example, in increasingly more homes is being conducted the installation of solar panels that collects the light that follows the star King and it is used to illuminate any room housing with which reduces significantly the use of electric power.
The economic or industrial exploitation of energy comprises several processes, which vary depending on the source used. One may mention, for example, the extraction of raw material (like the oil obtained from wells), processing (in the case of oil, its refinement) and its transformation into energy (by combustion, etc.).

### 5. Definition of energy

Energy is the ability that has a body to perform an action or work, or produce a change or transformation, and is manifested when it passes from one body to another. A matter has power as a result of their movement or its position in relation to the forces acting on it.
Various natural resources or phenomena of nature are able to supply and deliver power in any of its forms, so they are considered natural sources of energy and energy resources. There are two types, renewable sources, which to use them are not exhausted, such as sunlight, wind, rain, streams of rivers, etc.; and non-renewable sources, which are exhausted when they are employed, such as petroleum, natural gas or coal.
Energy is continually manifested us around, and occurs in nature in many forms; kinetic energy (energy that has a body in motion), potential energy (energy that has a body caused by its position in space), electricity (able to turn on a light bulb or operating a motor), energy Chemistry (contained in batteries, fuel or food), thermal, nuclear, wind, hydraulic, mechanical, radiant or electromagnetic energy, among others.
Is one of the properties presented by the energy that it is transferred; for example, when an object is heated, because another body, which has one higher temperature transfers energy in the form of heat, this is changing, so the process is some kind of work.
Energy is not created nor destroyed, it just transforms; This is the law of conservation of energy. All forms of energy can be turned into other forms through the appropriate processes; i.e., that power can take appearance of power, light, heat, sound and movement.
For example, conversion of energy that occurs when plugging in an iron, once connected, the electricity flowing through the resistance becomes caloric or thermal energy. Humans also use and transform the energy in our body to perform different jobs.
On the other hand, it should be noted that today the main source of energy comes from oil, remember that it is a non-renewable resource, and late or early it will be exhausted. Because of this, alternative energies, being implemented as the hydrogen, wind, solar, nuclear, geothermal, ocean energy, hydropower and bioenergy, however, some require high economic costs and are still inconvenient.

### 6. Energy concept

Energy is a word of Greek origin meaning working capacity. We can therefore make the following concept of power, from the point of view of physics, taking into consideration changes that power causes in natural, as its movement, elevation, transportation or heating phenomena:
It is the ability of a system for the development of a work., given by the position of the system (for example when we put a piece of iron to a magnet) which in this case it is called potential energy, and is the product of a body weight by the height that is; or it may be given by the speed of their masses, as when a hammer strikes on a nail (kinetic energy). The kinetic energy depends on the mass and the square of the velocity of the body.
The energy is very related to the mass of a body, relationship discovered by Einstein, who said that power has a directly proportional relationship to the ground from which it comes, with a proportionality equal to the square of the speed of light in a vacuum.
Energy, through chemical reactions, also produces chemical changes, such as when a log is burned. With combustion in the presence of oxygen, heat and chemical energy release occurs.
The energy can be solar, supplied by the Sun; thermal, when it manifests itself as heat (for example, an iron); light, where it produces light, such as a lamp; kinetics which as we have said, bring the bodies to move, as it possesses a car; hydraulic, as when in dams used energy that causes the fall of water; wind when the energy comes from wind, for example, used to move the blades of a windmill; Atomic, that is produced by the union or the atomic nuclei break; power, caused by the movement within a conductor of electrical charges, etc.
It can also be renewable, when it has a capacity of regeneration, as solar energy; or non-renewable, which tends to run out, such as oil.
The human body also need power to operate, we need it to run, think, walk, read, grow, and any everyday activity, increasing the movement energy need. Energy in the human or animal body, is incorporated through the diet.

### 7. Energy concept

A term that is used in physics to define that ability presenting to exercise a job and that is decreased in the same proportion to the amount of work generated by these bodies and systems.
Energy takes different forms and is able to transform one into another (energy conversion), but it is not able to create or destroy it (principle of energy conversion). Employed in its measurement units are on July, the electronvolt and the kilowatt-hour.
Joule and Carnot were the first people who tried to give an explanation of the conversion of heat into mechanical energy, and vice versa, definition that is linked to the Helmholtz, who relates the work done by an isothermal system with the internal energy and entropy of this.
By the mid 19th century, Thomson and Clasius proved what was called the "degradation of power", to show how diminishes the capacity of a work by an isolated system.
The formulation of the theory of Planck referring to quanta of energy, as well as propose a corpuscular and dashed for the energy, nature opened the passage to give explanation of effects such as the photoelectric and prompted to perform a corpuscular more in-depth study of the exchange of energy between bodies, which would later give rise to the emergence of quantum electrodynamics and quantum of radiation theory.
Turn Einstein, to demonstrate the equivalence of matter and energy, it extended the principle of the conservation of energy, including that of mass and energy, which initiates a stage of the use of nuclear power in multiple fields.

Custom Search