Eigenvalues and eigenvectors of the second derivative

2013-05-04T04:40:26Z

70.138.111.233: /* Dirichlet case */ corrected factor of two

{{Infobox Sailboat Specifications
|image =
|class_symbol =
|crew =
|loa = {{convert|18|m|abbr=on}}
|lwl =
|beam =
|draft =
|hull =
|updated = 19-APR-2010
|olympic = former
}}
The '''International Nine Metre Class''' is a ''construction class'', meaning that the [[boat]]s are not identical but are all designed to meet specific measurement formula, in this case [[International Rule (sailing)|International Rule]]. At their heyday, Metre Classes were the most important group of international [[yacht racing]] classes, and they are still actively raced around the world. "Nine" in the class name does not, somewhat confusingly, refer to the length of the boat, but the product of the formula; 9mR boats are, on average, 18 meters long.

==History==
The 9mR was used as an Olympic Class during the [[Sailing at the 1920 Summer Olympics|1920 Olympics]]. No entries were made.
The International Rule was set up in 1907 to replace an earlier, simpler handicap system which was often local or at best, national, and often also fairly simple, producing extreme boats which were fast but lightly constructed and impractical. The rule changed several times in history, and only about 50 boats were ever built.

==Rule development==
===1907 Rule===
Used from 1907–1920
:<math>
9.000 \mbox{ metres} = \frac{L + B + 1/3G +3d + 1/3\sqrt{S} - F}{2}
</math>
where
* <math>L</math> = [[waterline]] length (LWL)
* <math>B</math> = [[Beam (nautical)|beam]]
* <math>G</math> = [[chain girth]]
* <math>d</math> = difference between girth and chain
* <math>S</math> = [[sail]] area
* <math>F</math> = [[Freeboard (nautical)|freeboard]]

==Olympic results==
===1920===
No competitors entered the [[Olympic Games|Olympics]] in the 9 Metre.

==References==
{{reflist}}

{{Olympic class sailboats}}
{{Olympic Games Sailing}}
{{Keelboats worldwide}}

{{DEFAULTSORT:09}}
[[Category:Keelboats]]
[[Category:Olympic sailboat classes]]

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Eigenvalues and eigenvectors of the second derivative