Energy - a comprehensive concept as it is present everywhere. At the mention of this word the ordinary person will be occurred, most likely, by the electric power used everywhere for lighting of rooms, operation of the household and computer equipment. Meanwhile, in science different forms of energy are considered.
Instruction
1. Energy in science is a physical quantity, a measure of different forms of motion and interaction of forms of matters, their transition from some forms to others. Depending on form of motion of matter distinguish such forms of energy as mechanical, electromagnetic, chemical, internal, nuclear, etc. But this division is in many respects conditional. In physics use of a concept of energy is considered expedient when size remains at the movement, i.e. the considered system has to be uniform in time.
2. Thermal energy represents energy of chaotic motion of the molecules. It turns into other types of energy with losses. Electromagnetic - the energy concluded in magnetic field (it also depending on a situation is divided into electric and magnetic). Gravitational is understood as potential energy of a system of the particles (or bodies) gravitating to each other. Nuclear (or atomic) energy contains in atomic kernels and is distinguished at nuclear reactions. This energy is applied in nuclear power plants to obtaining heat (which is used for ensuring heating and the electric power) and also in destructive nuclear weapon and hydrogen bombs. In thermodynamics (section of physics) there is a concept of internal energy - the sum of energy of thermal movements of a molecule and molecular interactions. It is not all list of forms of energy.
3. The theory of relativity of Einstein according to which there is a communication between energy and weight is connected with a concept of energy. It is expressed in formula E = to mc2: energy of a system (E) is equal to its weight (m) increased by the speed of light in a square (c2). As weight it is accepted to understand body weight at rest, and as energy - internal energy of a system. There is a law of energy conservation. It is that energy does not occur from anywhere and does not disappear in anywhere. It only passes from one form into another.