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Old 09-19-2012, 03:53 PM   #58
A.Reader
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Join Date: Sep 2012
Location: K'zoo
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Default possible mistakes in spreadsheets

@stoneage Thanks for your many technical posts. This is an interesting attempt to develop a new way of looking at the weight parameters of racquets.

However, I believe there is a mistake in the formula in your effective_mass.xlsx spreadsheet. There is an extra factor of 2 in the denominator there. When you take that out, the plots become monotonic with 15/r and you get much larger effective masses on the right side.

In the eqv_mass_norm.xlsx spreadsheet, I don't understand the expression for the reference racquet that you use in the denominator there. Can you explain how Ip for the reference racquet equals 320 (1033 + 50*r + r*r) ?

Using I[end] = (M*L^2)/3 for a uniform rod, I get
Ip = 320 (70*70/3 + r*r) for the reference racquet. This makes the curves look quite different.

Anyways, thanks for posting something that was motivating enough to get me to finally de-lurk!
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