The law of conservation of energy is the basis of the principles

In his daily activities, a person uses a variety of energy: thermal, mechanical, nuclear, electromagnetic, etc. However, for the time being we will consider only one of its forms - mechanical. Moreover, from the point of view of the history of the development of physics, it began with the study of mechanical motion, forces and work. At one of the stages in the formation of science, the law of conservation of energy was discovered.

When considering mechanical phenomena, the concepts of kinetic and potential energy are used. It has been experimentally established that energy does not disappear without a trace, from one species it turns into another. We can assume that what has been said in the most general form states the law of conservation of mechanical energy.

First it must be noted that, in sum, the potential and kinetic energies of the body are called mechanical energy. Further it is necessary to bear in mind that the law of conservation of total mechanical energy is valid in the absence of external influence and additional losses caused, for example, by overcoming the forces of resistance. If any of these requirements is violated, then with a change in energy, its losses will occur.

The simplest experiment that confirms these boundary conditions, everyone can conduct independently. Raise the ball to the height and release it. After hitting the floor, he will jump and then fall again to the floor, and again he will jump. But each time the height of his rise will be less and less, until the ball is frozen motionless on the floor.

What do we see in this experience? When the ball is stationary and at altitude, it has only potential energy. When the fall begins, it has a speed, and therefore kinetic energy appears. But as the fall decreases, the height with which the movement has started becomes smaller and, correspondingly, its potential energy becomes lower, i.e. It turns into kinetic. If we carry out the calculations, we find out that the energy values are equal, which means that the energy conservation law is satisfied under such conditions.

However, in such an example, there are violations of two previously established conditions. The ball moves in the air and is resisted from its side, albeit small. And energy is spent on overcoming resistance. In addition, the ball collides with the floor and bounces off, i.e. He experiences an external effect, and this is the second violation of the boundary conditions that are necessary for the law of conservation of energy to be valid.

Eventually the jumps of the ball will stop and he will stop. All available initial energy will be spent on overcoming air resistance and external impact. However, in addition to the transformation of energy, work will be performed to overcome frictional forces. This will lead to the heating of the body itself. Often the heating value is not very significant, and it can only be determined by measuring with accurate instruments, but a similar temperature change exists.

In addition to mechanical, there are other types of energy - light, electromagnetic, chemical. However, for all varieties of energy, it is true that from one species transition to another can occur, and that under such transformations the total energy of all species remains constant. This is a confirmation of the general nature of energy conservation.

Here we must take into account that the transition of energy can mean and its useless loss. With mechanical phenomena, this is evidenced by the heating of the surrounding environment or interacting surfaces.

Thus, the simplest mechanical phenomenon allowed us to determine the law of conservation of energy and the boundary conditions that ensure its implementation. It was found that the conversion of energy from the existing species to any other is carried out, and the general character of the law is revealed.