To answer the question, what fluctuationsare called harmonic, it should be borne in mind that these physical phenomena - one of the most common in nature. It is probably difficult to indicate a sphere where harmonic oscillations would not be present. The most common areas of physical theory in which oscillatory processes are investigated are mechanics, electrical engineering and electronics, radar and hydroacoustics, and others.
All without exception these areas arethat the nature of oscillatory processes, as a rule, is the same, and therefore there is a general classical theory for their description. Parametric differences of oscillatory processes are due only to the environment of their occurrence and external factors that can affect the oscillatory motion. The simplest example of oscillatory movements with which we daily face in everyday life are, for example, oscillations of the pendulum of a clock, or electric current.
Fluctuations in nature of their flow arefree and harmonic. Free vibrations are also called eigenmodes, which emphasizes that they have external environmental disturbances as their source, which take the physical body out of static equilibrium. An example is a weigher, which is suspended from a thread, and which we push with a certain oscillatory process.
More significant place in the physical theorypaid to the study of the phenomenon of harmonic oscillations. The study of their nature is precisely the theoretical basis on which the study of the narrower aspects of oscillatory processes is based, namely, their occurrence in various environments - mechanics, electricity, chemical transformations and reactions.
In order to describe harmonic oscillations in physics, such basic parameters as period and frequency are used.
Based on the previously formulated by usthe assertion that there is some general universal model of the occurrence of oscillatory processes can logically come to the conclusion about the existence of some universal quantities characterizing these oscillations. Consequently, the aforementioned parameters — the period and frequency — are peculiar to all types of oscillations, regardless of the source of their generation and the medium of their occurrence.
Frequency is a quantitativea value indicating how many times during a certain period of time, the physical body has completed the process of changing its static state and returned to it. For example, you can count how many times, the same weight made a hesitation after we pushed it until it was completely stopped.
The period in this process will show the time period for which this weight will deviate from the original position and return to the original one in one oscillation.
Investigating harmonic oscillations, shouldunderstand that the period and frequency are objectively linked by a general formula that ultimately determines the graph of harmonic oscillations. To more objectively understand what it is, it should be noted that there are other parametric indicators - amplitude, phase, cyclic frequency. Their use allows us to use trigonometric functions to describe oscillatory processes. The most common formula for plotting is the following: s = A sin (ωt + α). This formula, also called the equation of harmonic oscillations, allows you to build a graph of the oscillatory process, which in its simplest form is a simple sinusoid. In the above example, the formulas, the coefficients ω and α show exactly which transformations need to be performed with the sine wave, in order to display a specific oscillatory process.
With more complex oscillatory phenomena, their graphic description is naturally complicated. This complication is due to the influence of two main factors:
- the nature of the process, that is, by what particular vibrations are investigated - mechanical, electromagnetic, cyclic or other;
- the environment within which oscillatory phenomena are generated and carried out - air, water or other.
These factors significantly affect all parameters of any oscillatory process.
