A quite familiar picture is a concert hall, a virtuoso violinist on the stage, the hall is filled with numerous music lovers listening to the enchanting sounds. Without touching the artist’s skill, everything that happens is possible thanks to the effect of acoustic resonance. So what is resonance?
At the mention of this term, an ancient story about the destruction of the bridge by a company of marching soldiers is immediately recalled. The fighters, having ascended upon it, continued to march in step, in foot. As a result, the bridge collapsed.
Or the most common picture is a child on a swing. And someone nearby, swinging them. Insignificant efforts applied at the right time, allow to achieve a large amplitude of vibrations and give the baby great pleasure.
Without going into a mathematical description of the occurring phenomenon, let us try to qualitatively understand what resonance is. A physics textbook defines this effect as an increase in the amplitude of oscillations of the system when the frequency of the external action and the natural frequency coincide. A little explanation. Oscillation frequency - the number of oscillations per second.
Yes, it’s not entirely clear, the words seem to be all familiar — resonance, physics, the frequency of natural vibrations. What does it mean?
For simplicity of perception, let us recall another example - between two pillars (let it be two sides of the stream) there is a long wide board, it sways a little, hesitates, but it looks reliable. Going through the stream seems to be simple, get up on the board and go. But here's a bad luck. At a certain speed, or in other words, the frequency of steps, the board begins to swing strongly, threatening to lose the walker. In this case, the resonance conditions are again fulfilled - the frequency of oscillations of the board itself coincides with the frequency of the steps of the pedestrian. As a result, the amplitude of the oscillations increases significantly, the result of such amplification may be unexpected water procedures.
A similar phenomenon is extremely widespread in various fields. In electronics, medicine, in music, with which the description of the resonance effect began. This phenomenon is often useful, allowing, for example, to amplify a weak signal. The sound of a violin string is amplified by its body acting as a resonator, i.e. an amplifier at a specific frequency. And the sound of the violin itself is enhanced by the good acoustics of the room.
A slightly different application of resonance is amplification of a radio station signal. Everything is simple again. Radio waves bring the signal to the antenna, from there it enters a special input circuit, changing the parameters of which can amplify the signal of the desired frequency. This is what we do when we turn the knob of the receiver settings in search of the desired radio station. As a result of such amplification, the signal of the allocated radio station becomes stronger and is successfully perceived by the receiver.
From the above examples, the answer to the question of what is resonance becomes clear. This is a general increase in effort obtained by synchronizing the capabilities of the system itself and external influences. As a final example - an attempt to get out of the dirt on a car by the “buildup” method. The driver begins to alternately move the car forward and backward. Back, then acceleration forward, in case of failure acceleration again, but already backward, and again forward. With this approach, engine power is combined with inertia of movement and in many cases allows you to overcome a difficult place.
Even the modest number of examples cited is enough to understand how widely the phenomenon of resonance is applied in technology and everyday life.
The cited material answers the question of what resonance is. Examples of the manifestation of resonance phenomena in various fields of technology and culture are considered.