Sound waves(a neat experiment)

[Richard Brekne]

Ok boys and girls... heres an interesting experiment to explain, and
interesting enough completely removed from the disscussion as well.

Terry and Greg.. you guys have a bit of soundboard stuff laying around so this
would be really easy to construct.. in like 10 minutes or so..

Take a peice of soundboard stock... say 12 inches by 8... or something like
that. Glue two peices of 2 by 6 8 inches long to the butt ends to simulate a
kind of rim. Then take a nice quality big o'l tuning fork and measure the
diameter of the end you hold in your hand. Drill a hole in the middle of the
board just big enough so that the fork will fit real tightly in and sink it in
full depth.

NOW !!... grin.... place the "panel" between your knees so that you can put
pressure on the "rim" and create varying degrees of crown in the panel. Hit the
fork with say a number 88 hammer... or something so that you get it vibrating
real strong and listen to the change in the volume produced when you change the
amount of bend in the "panel".

Experiment courtesy (in this instance) of Nils Henrik Jansen, RPT Bergen.

As far as our discussion goes... note that the fork has no possibility of
vibrating the board up and down. Or what ?


--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html