In nature, everything is interconnected and continuously interacts with each other. Each part of it, each component and element is constantly exposed to a whole complex of forces.
Despite the fact that the amount of forces in nature is quite large, all of them can be divided into four types:
1. Gravitational forces.
2. Forces of an electromagnetic nature.
3. Forces of a strong type.
4. Forces of a weak type.
Gravitational forces become visible only on a cosmic scale. Forces of an electromagnetic nature are forces that are manifested in the interaction of particles having certain electrical charges.
The strength of elasticity is one of the most significant forces in nature. When a body undergoes a deformation process, a special force arises inside it, which is equal to the deformation force, but with the opposite sign. The elastic force is directed against the deformation of the body. Its varieties are the tension force, the reaction force of the support.
In physics, there is such a thing as elastic deformation. Elastic deformation is a phenomenon of deformation in which it disappears after external forces cease to act. After such a deformation, the body takes its original shape. Thus, the force of elasticity, the definition of which says that it arises in the body after elastic deformation, is a potential force. A potential force, or conservative force, is such a force in which its work cannot be dependent on its trajectory, but depends only on the start and end points of application of forces. The work of a conservative or potential force along a closed path will be zero.
We can say that the elastic force has an electromagnetic nature. This force can be estimated as a macroscopic manifestation of the interaction between the molecules of a substance or body. In any case, in which there is either compression or extension of the body, the elastic force is manifested. It is directed against the deforming force in the direction opposite to the displacement of the particles of a given body, and is perpendicular to the surface of the body undergoing deformation. Also, the vector of this force is directed in the direction opposite to the deformation of the body (displacement of its molecules).
The calculation of the value of the elastic force arising in the body during deformation occurs according to Hooke's law. According to him, the elastic force is equal to the product of the body stiffness and the change in the deformation coefficient of this body. According to Hooke’s law, the elastic force arising at a certain deformation of a body or substance is directly proportional to the elongation of this body, and it is directed in the direction opposite to the direction in which the particles of this body move relative to other particles at the time of deformation.
The stiffness index of a particular body or a proportional coefficient depends on the material used to make the body. Also, stiffness depends on the geometric proportions and shape of the body. In relation to the elastic force, there is still such a thing as mechanical stress. Such stress is the ratio of the modulus of elasticity to unit area at a given point in the cross section under consideration. If we connect Hooke’s law with voltage of this type, its formulation will sound somewhat different. The stress of a mechanical type that occurs in a body during its deformation is always proportional to the relative elongation of this body. It must be borne in mind that the effect of Hooke's law is limited only by small deformations. There are deformation limits under which this law applies. If they are exceeded, then the elastic force will be calculated by complex formulas, regardless of Hooke's law.