In mechanics talk about two types of energy : kinetic and potential.Kinetic energy concerns direct traffic, the potential points to the possibility of movement in the future.Potential energy - the nominal size, depending on the chosen system otscheta.Dlya illustration can be considered a mathematical pendulum.So called ball hanging by a thread, which makes sustained oscillations from side to side.In the extreme positions, he stops, but its potential energy at the same time maximum.Walking through the center, the ball moves with the greatest speed and has a maximum kinetic energy.The potential energy of the ball in the middle position is zero.At all points the sum of kinetic and potential energy ball - its total mechanical energy
- remains postoyannoy.Matematichesky pendulum - abstraction, an ideal model.In the case of real physical pendulum, the system includes the friction force and air resistance.Fluctuations ball fade, and it seems that its energy decreases.In fact, it is not.Just part of the mechanical energy goes into the inner - the energy of the thermal motion of atoms and molekul.Sily friction and resistance are called dissipative forces (from the English. Dissipate - dissipate).They "scatter" mechanical energy: thanks to them, it gradually turns into the interior, the heat.Surely you've noticed time and again as the friction body heat?Making fire by friction it is based on the same printsipe.Itak, under the influence of dissipative forces of inelastic collisions and other processes in the body temperature increases.This is due to an increase in kinetic energy atoms and molecules in the body of their chaotic dvizhenii.Po the development of science, is required to introduce new types of energy : electromagnetic, nuclear and others. The concept energy, thus continuously rasshiryaetsya.Printsip save energy pushes scientists in the direction of new research.Any apparent violation of the law says that there are phenomena that do not fit into the framework of existing scientific theories.This was the case at the opening of radioactivity and particle neutrino.
- «Mechanics", DVSivukhin, 2006.