Re: [Phys-l] frequency and wavelength of sound in air

[Bernard Cleyet <bernardcleyet@redshift.com>]

This is a lab at the Naval Postgraduate School in Monterey.   The  
boxes (no tops) are lined w/ acoustical foam*.  Two piezoelectric  
transducers are used.  Not surprisingly, the labs are heavily  
weighted to ocean acoustics.  They not only have three large pools in  
the basement, but also a rather good home made anechoic chamber and  
one lab. room is used as an echoic chamber.   They also have a large  
sand pile w/ piezo detectors and a thumper.  I leave it to youall to  
guess its purpose.  [hint:  the trailer for analysis and thumper  
driver reminds me of those used to find oil.]

* can only be used for a few hours before becoming impregnated w/ water.

bc's first job was topping up and running the filtering system  
periodically.


p.s. I wonder is there is an acoustical frequency doubling, etc.   
analogous to that in optical non-linear crystals?


On 2009, Apr 04, , at 20:19, curtis osterhoudt wrote:

> Yes, a standing wave can be established in a nearly-1D water  
> channel; however, if you are referring to a surface wave (as at the  
> air-water interface), the behavior is quite complicated (but  
> understandable, and fascinating, to good undergraduates).