(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A cable passes around three 2-in-radius pulleys and supports 2 blocks as shown. Pulleys C and E are locked to prevent rotatoin, and the coefficient of friction between the cable adn the pulleys are static = .20 and kinetic = .15. Determine the range of value of the weight of black A for which equilibrium is maintained (a) if pully D is locked, (b) if pully di is free to rotate.

http://img98.imageshack.us/my.php?image=circleproblemit0.jpg

2. Relevant equations

ln(T2/T1) = static * angle

3. The attempt at a solution

The main problem i'm having is determining the angles to be used. I can see it's a 30/60/90 triangle. So i tried using pi/3 for the D and pi/6 for C, and that didn't work.

Then i used pi/3 still for D and changed pi/6 to 2*pi/3. And that didn't work. If anyone could help me with just the angles that'd be much appreciated. I think i have everything after that down. Thanks for all the help :D

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# Homework Help: Belt friction - determining angles

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