Hi Folks Attached is the easily read article by Young from 1952. In particular I wish to draw your attention to the paragraphs which are attached to equations 8 and 9 where these two yield the following interesting relationship. Q/p = 25.5 *10^10 (relationship 1) Q being the Young Modulus and p being the string density. I use dynes /cm^2 for Q and gm per cm^3 for p as in Youngs paper. This relationship implies directly that if one has the value for either Q or p one can calculate the other. And indeed later on in his paper in the 7th paragraph of the section entitled Three Steinway Pianos he does just that citing a Q value of 20.0 * ^11 dynes per cm^2 and a density of 7.83 g/cm^3. If one on the other hand one uses the values for the Youngs Modulus and densities found in McFerrin one comes up with a very significant error in regards to relationship 1. The same kind of error occurs if one uses the published wire data on Pure Sounds site for all types of wire he gives data for, and just about everywhere you look outside of Youngs own paper. The point is that Youngs equations in the paper from 1952 in particular his equations relating to B (the coefficient of inharmonicity) yield the relationship above (relationship 1). If there is more then slight divergence in the relationships between the real (measured) for Q and p compared to Youngs formula for B... then something must be wrong with the formula itself..... OR... the measured values are in error. I would think the later is more likely when it comes down to it .... so the question is which of the measured values (Q or p) we see out there in the world is more likely to be the most dependable ? I would guess at density (shot in the dark really)... in which case if one knows (accurately) the density of the material then its Youngs modulus is a GIVEN....a direct result of the relationship above (1). It HAS to be... or Young was wrong. Comments are very welcome. Thanks RicB -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/20070116/88f590d5/attachment.htm
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