ResonanceRESONANCE: ” The property whereby any vibratory system responds with maximumamplitude to an applied force having the a frequency equal to its own. “In english, this means that any solid object that is struck with a soundwave of equal sound wave vibrations will amplitude the given tone.
This wouldexplain the reason why some singers are able to break wine glasses with theirvoice. The vibrations build up enough to shatter the glass. This is calledRESONANCE. Resonance can be observed on a tube with one end open.
Musical tones can beproduces by vibrating columns of air. When air is blown across the top of theopen end of a tube, a wave compression passes along the tube. When it reachesthe closed end, it is reflected. The molecules of reflected air meet themolecules of oncoming air forming a node at the closed end.
When the airreaches the open end, the reflected compression wave becomes a rarefaction. Itbounces back through the tube to the closed end, where it is reflected. the wavehas now completed a single cycle. It has passed through the tube four timesmaking the closed tube, one fourth the length of a sound wave. By a continuoussound frequency, standing waves are produced in the tube.
This creates a puretone. We can use this knowledge of one fourth wavelength to create our owndemonstration. It does not only have to be done using wind, but can also bedemonstrated using tuning forks. If the frequency of the tuning forks is known,then v=f(wavelength) can find you the length of your air column. Using a tuning fork of frequency 512 c/s, and the speed of sound is332+0. 6T m/s, temperature being, 22 degrees, substitute into the formula.
Calculate1/4 wavelength V=f(wavelength) wavelength=V/f =345. 2 (m/s) / 512 (c/s) =0. 674 m/c1/4 wave. =0. 674 (m/c) / 4 = 0.
168 m/cTherefore the pure tone of a tuning fork with frequency 512 c/s in a temperatureof 22 degrees would be 16. 8 cm. The pure tone is C. If this was done with other tuning forks with frequencies of 480, 426. 7,384, 341.
3, 320, 288, and 256 c/s then a scale in the key of C would be produced. There are many applications of this in nature. One example of this would bethe human voice. Our vocal chords create sound waves with a given frequency,just like the tuning fork.
One of the first applications of the wind instrument was done in ancientGreece where the pipes of pan were created. pipes of hollow reeds were boundtogether, all of different length. When Pan, the god of fields, blew across hispipes, the tones of a musical scale were heard. Later reproduction of the sametype were created and musical instruments are heard all over the world thanks tothe law of resonation. BibliographyGranet, Charles; Sound and Hearing; Abelard-Schuman, Toronto; 1965Freeman, Ira M.
; Sound and Ultrasonics; Random House; New york; 1968Freeman, Ira M. ; Physics Made Simple; Doubleday, New York; 1965Jones, G. R. ; Acoustics; English Univ. Press; London; 1967White, Harvey E; Physics and Music; Saunders College, Philadelphia; 1980Funk and Wagnall; Standard Desk Dictionary; Harper Row, USA; 1985 Science
