Oscillatory processes - one of the mostwidespread phenomena in nature. Their research deals with various branches of knowledge, first of all, physics. To answer the question of what oscillations are called free, it should be taken into account that this category is the initial one in the study of the whole variety of vibrational phenomena that occur in nature.
Distinguish their following types, classified according to the following reasons.
By physical nature distinguish between mechanical, electromagnetic and mixed, combining the characteristics of those already named.
By the method of flowing in the surrounding environments, the following oscillations are distinguished:
- forced, that is, those that are called andoccur under the influence of various kinds of external perturbations of the media in which they occur. In this case, the periodicity condition of these perturbations must be observed;
- free oscillations, called stillintrinsic, which are initiated by the internal properties of the system and which are characterized by mandatory damping, when the action of internal forces ceases or decreases;
- auto-oscillations - such as are characterized bythe presence of some potential (potential energy) in the system that ensures the fulfillment of oscillations. The main thing is that the free oscillations differ from self-oscillations, the dependence of the amplitude does not depend on the initial initiating force pulse, but on the characteristics of the physical system itself;
- parametric - this is the oscillations that are formed when the specified system is deliberately assigned to a vibrational system of a parameter that acts as a manifestation of the properties of the external environment;
- random oscillations are those in which the factors affecting the oscillatory process are random, not parametric.
Summarizing these characteristics, one can makethe conclusion that in the most general form, oscillations are repeating with a certain periodicity of a certain system with respect to its equilibrium state. The most common areas of manifestation of oscillatory processes in nature are mechanical phenomena, chemical, wave and electric, astronomical, electromagnetic and other. A common property of all types of oscillations, without exception, is that they are directly related to the energy transition - the conversion of one type of energy into another.
As already noted, the starting point instudy of the nature of oscillatory processes, is an investigation of such a form as free oscillations. Their main characteristics are the following parameters:
- Amplitude (A) - the largest deviation of the system from its equilibrium state (most often the average value is used);
- period (T) - a certain period of time, during which it is possible to fix repetitions of system states;
- frequency of free oscillations (f) - the number of oscillations that the system makes for a certain unit of time. This parameter is measured in hertz (Hz).
The relationship of these parameters reflects the formula thatcharacterizes free oscillations as a phenomenon. For different oscillatory systems, the parameters in this formula are included in different combinations, depending on which particular system is being considered.
For example, in the simplest oscillatory circuit, the period and frequency are related by the formula: f = 1 / T, from which it can be seen that the period and frequency are the reciprocals.
If we consider the free oscillations thatoccur in a system such as a spring that is fixed statically, having a certain elasticity (k), then here it is necessary to turn to the second law of Newton. Taking this into account, the formula reflecting the properties of the considered oscillatory system takes the form: F = -kx. This indicates that if we neglect the values of the frictional forces and assume the mass to be constant, then such a system will always oscillate with the same period, even with different amplitudes and initial conditions of their origin.
