Conservation laws in mechanics

In educational institutions, wise teacherstell their students that there is a conservation law in mechanics. Its meaning lies in the fact that energy in a closed system can not irrevocably disappear, wasted on the performance of any work. In such processes, there is not a disappearance, but a transformation of energy of one kind into another. For example: click the switch - and the electric bulb flashes brightly. The meter regularly calculates the energy expended. Where does it disappear? It's simple: the electric current does work, while the energy is converted into radiation and heating. In other words, the laws of conservation in mechanics are relevant for any mechanical device (or even electrical one - the difference is only in a kind of primordial energy and the name of the same phenomenon). In fact, the law of conservation is a fundamental principle, according to which the entire universe lives.

First of all, it is necessary to decide what iskinetic and potential energy. Simply put, the first is the energy of the body movement, which characterizes the work performed by the body. And the second is the temporarily unrealized energy of the system of bodies, determined by the nature of the interaction and the location of objects in the system itself. It is quite natural that the term originated from the Latin word meaning "opportunity." In mechanics, these two kinds of energy are transformed one into another.

The conservation laws in mechanics work as followsway. For example, an object thrown upwards at the moment of receiving a pulse has the maximum value of the kinetic energy. Accordingly, the speed of its movement is the highest at the initial moment. Gradually, it decreases, because the kinetic energy is converted into a potential one. As a result, the object slows down and stops. This means that all of its stock of the initial pulse energy has been transformed into a potential energy and accumulated in the system. Further, due to gravitational action, the object begins to fall. The potential energy is converted back to kinetic. It is not difficult to guess that at the initial moment of motion the velocity is minimal, but it gradually increases, since the value of the kinetic energy of the system increases. It should be noted that in this case, despite the influence of the Earth's magnetic field (additional pulse), the total sum of the energies of the system remains unchanged.

To better understand conservation laws in mechanics,it makes sense to turn to your own life experience. Surely, as a child, everyone dropped a small, but massive ball or an ordinary ball on the metal base. At the same time, he jumped up and fell again. This was repeated until the movement spontaneously ceased. But what about the law of conservation of energy in mechanics? After all, logically, the potential energy of the falling ball must be fully transformed into kinetic, and vice versa. Almost "perpetual motion". Is it possible that in this case the conservation laws in mechanics are not satisfied? In fact, in this situation, the system is affected by friction about the air molecules and internal deformations of the surface and ball. It is they who "steal" their part of the energy, because of what the ball gradually ceases to bounce (by the way, therefore, in the framework of classical mechanics it is impossible to create a perpetual motion machine).

The universality of conservation laws allowsuse them not only in the calculation of the interaction of the systems of the macrocosm, but also, in part, in the microcosm. Neither the trajectory of the movement, nor the type of forces acting on the system, affects the result-conservation laws work!