Ability of a physical system to produce a job.
This definition, although it is the most widespread, can be misleading because of the vagueness of the term "capacity", and therefore, it is better to define the energy as what, when a work occurs, decreases in an amount equal to the work produced. Energy, then, is measured in the same units as labor. History of the study of energy
The notion of energy appears for the first time from the investigations of Joule and Carnot on the conversion of heat in mechanical work and thanks to the theory of Helmholtz in which it connects…
Kinetic energy is the energy contained in a body due to being in motion. The kinetic energy is the amount of work needed to accelerate a body of a given mass to a certain speed (linear or rotational). This energy obtained during acceleration will remain unchanged as long as this body does not change its speed.
In classical mechanics, the linear kinetic energy (without rotation) of an object of mass m traveling at velocity v is ½ · m · v2. In relativistic mechanics it is a good approximation only when the speed is much less than the speed of light.…
In physics, potential energy is the energy an object possesses because of its position in a force field or that a system has because of the configuration of its parts.
There are many types of potential energy, but the most common are:
- Gravitational potential energy that depends on the vertical position and mass of an object.
- Elastic potential energy of an extended spring
- Electric potential energy of a charge in an electric field.
The unit of measurement of the International System of Units for Energy is the joule (J).
Chemical energy is the potential of a chemical to undergo a transformation through a chemical reaction or to transform into other chemicals. Forming or breaking chemical bonds involves energy. This energy can be absorbed or evolved from a chemical system.
The energy that can be released (or absorbed) by a reaction between a set of chemical substances is equal to the difference between the amount of energy of the products and the reactants. This change in energy is called the internal energy of a chemical reaction.
The internal energy change of a process is equal to the change…
We define electrical energy as the form of energy that results from the existence of a potential difference between two points. When these two points are brought into contact by an electric conductor we obtain an electric current. Physical aspects of electrical energy
From the physical point of view, electrical energy is negative electric charges (electrons) that move through the electric conductor, usually metallic, due to the potential difference between its ends. The reason metal conductors are usually used is because they have more free electrons.
Electric charges moving…
Renewable energies are those energies using an energy source or fuel which is considered inexhaustible or can be regenerated at the same rate at which it is consumed.
The classification of renewable energy depends on natural resources exploited. Solar energy
We distinguish two ways of using solar energy:
- Solar thermal
- Solar photovoltaics
The use of solar thermal is to use heat energy obtained from solar radiation to heat a fluid, depending on its temperature,…
To explain the history of nuclear energy we could distinguish three major stages:
- Physical and chemical scientific studies of the elements.
- The development of the nuclear bomb during World War II.
- Use of nuclear energy in the civil field.
Scientific studies cover this whole period since the first Greek philosophers began to define atoms, until the development of the first nuclear bomb. In this process, different scientists discover the presence of electrons, neutrons and protons and properties that make one atom more radioactive than another.…
A nuclear power plant is a facility for obtaining electrical energy using nuclear energy.
Its operation is similar to that of a thermal power plant or that of a solar thermal plant: from a source of energy thermodynamics is used to obtain heat, with the heat to get steam and with the steam to drive a turbine that will generate electricity.
The difference between the different types of electrical installations is in the energy source: a nuclear power plant uses the heat released in the nuclear fission reactions of certain atoms, in a thermal power station the heat source (thermal…
Heat energy is the manifestation of the energy in the form of heat. All materials have atoms that form molecules with constant movement and vibration. This movement of atoms generates a kinetic energy called heat or heat energy.
If we increase the temperature of any element, we increase its heat energy. However, when we increase the heat energy of an element it's not guarantee that its temperature is increased. The temperature is the same during the stage of changes. A good example is heating some water. Little by little we obtain heat…
Nowadays, the main use given to nuclear energy is the generation of electric power. Nuclear power plants are responsible of doing this process. Almost all nuclear power plants in production are using nuclear fission since the nuclear fusion, despite being under development, is currently unfeasible.
The operation of a nuclear power plant is identical to the operation of a thermoelectric power plant operating with coal, oil or gas, except in the way of providing heat to the water for converting this one into steam. In nuclear reactors this process of producing heat is made by the fission…
In 1974 the French government decided to rapidly expand production capacity of nuclear power in France just after the first oil crisis. This Decision n was made in the context of a France with substantial competition in engineering, but few indigenous energy resources. Nuclear power, with the cost of fuel is a relatively small the total cost, in this sense, getting a reduction in imports and greater energy security could.
As a result of the decision of 1974, France currently has a high level of energy independence and almost the lowest cost electricity in Europe. It also has a level…