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<br>While I was digging about the net on this one I ran into the following:
<br>The following is THE equation for EVERYTHING you desire (and then some):
<p> n * sqrt(T/u)
<br>f = ------------
<br> 2L
<p>f = the frequency of a streched string (or wire)
<br>n = 1 for FUNDAMENTAL frequency (which is what we want)
<br>T = Tension in wire
<br>u = (actually a greek mu) mass per unit length of wire
<p>Solve this for T and we get
<p>T = 4 L^2 F^2 u
<p>The mass per unit length (mu) is defined as
<p> R A
<br>u = ---
<br> g
<p>R = (rho in greek) = density of wire material
<br> steel = 0.283 lb/in^3 brass =
0.310 lb/in^3
<br>A = cross-sectional area of the wire (pi * r^2) or (pi * (d/2)^2)
<br> r = wire radius or d = wire diameter
<br>g = gravitational constant (32.2 ft/sec^2)
<p>This reduces to
<p> pi * (d/2)^2 * R * F^2 * L^2
<br>T = ------------------------------
<br> 96.6
(the 96.6 is (32.2 * 12 in/ft) / 4 )
<p>so, for #8 steel wire (d = 0.020"), 16 in long, tuned to A (440 hz)
<br>it will be under 45.6 lbs tension!
<p>You will need to dig up a table of string #s to find the diameter
<br>(#6 = 0.016" #8 = 0.020" #10 = 0.024" #12 = 0.029") and other
<br>densities if you don't use steel or brass wire. ANY college physics
<br>book should also have these equations as well as the wire diameter
table
<br>and the wire densities.
<br>
<br>
<p>Just in case anybody is interested....grin
<br>
<blockquote TYPE=CITE><font face="Arial"><font size=-1></font></font> <font face="Arial"><font size=-1>Djalma
Carvalho - Brazil</font></font></blockquote>
<p>--
<br>Richard Brekne
<br>RPT, N.P.T.F.
<br>Bergen, Norway
<br><A HREF="mailto:Richard.Brekne@grieg.uib.no">mailto:Richard.Brekne@grieg.uib.no</A>
<br>
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