Correct me if I'm wrong but wouldn't a longintudinal wave be a sound type of wave, only in a different medium? It has speed that can be measured and reflects off of things. When something vibrates it is because it is under tension and fixed with a flexible center or end so it wants to return to center. This can happen on a cellular or fiber level as in a block of wood. Keith Roberts On Wed, May 13, 2009 at 6:11 AM, Keith Roberts <keithspiano at gmail.com>wrote: > > > On Tue, May 12, 2009 at 10:21 AM, <afmamh7 at bellsouth.net> wrote: > >> I am not an acoustician, but I think it is incorrect to consider sound and >> vibration as two different types of energy. Sound IS vibration. >> >> > >> Sound is not vibration. Sound is an impulse that is a wave of air. It >> leaves from it's point of origin and never goes back unless acted upon by >> another force. It is confusing that it does have frequency and amplitude. >> Take the wave pattern caused by dropping a rock in a pond. The resultant >> waves have direction, amplitude and frequency but we don't call it >> vibration. Sound originates from a point source and disperses in the same >> manner as the water waves do. > > > >> In vibration, the energy returns and crosses the center line of origin. >> Back and forth motion is vibration. > > > Keith Roberts > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20090513/c043bdfb/attachment.htm>
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