Physics Help Forum Shear stress formula

 Thermodynamics and Fluid Mechanics Thermodynamics and Fluid Mechanics Physics Help Forum

 Mar 9th 2016, 05:28 AM #1 Senior Member   Join Date: Jun 2014 Posts: 306 Shear stress formula how to get the formula of shear stress (tau) ? i got (-dp/ds -ydz/ds )(r/2) instead of -d(p+yz)/ ds (r/2) as in the book , if it's d(p+yz)/ ds (r/2) m , i would get (-dp/ds -ydz/ds-z(dy/ds) )(r/2) ,, right ? Attached Thumbnails
Mar 9th 2016, 05:54 PM   #2
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Join Date: Jun 2014
Posts: 306
 Originally Posted by ling233 how to get the formula of shear stress (tau) ? i got (-dp/ds -ydz/ds )(r/2) instead of -d(p+yz)/ ds (r/2) as in the book , if it's d(p+yz)/ ds (r/2) m , i would get (-dp/ds -ydz/ds-z(dy/ds) )(r/2) ,, right ?
anyone her?

 Mar 10th 2016, 06:39 AM #3 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,347 You used the symbol 'y' in your formula, but it's actually gamma. I haven't looked at this very closely, but I assume that gamma is a constant, so your version and the book's versions are identical. Last edited by ChipB; Mar 10th 2016 at 06:43 AM.
Mar 10th 2016, 05:37 PM   #4
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 Originally Posted by ChipB You used the symbol 'y' in your formula, but it's actually gamma. I haven't looked at this very closely, but I assume that gamma is a constant, so your version and the book's versions are identical.
the y actually stands for specific weight

 Tags formula, shear, stress