Static friction is my answer correct?

AI Thread Summary
The discussion revolves around a homework problem involving static friction and the maximum weight that can be hung on a hanger's arm attached to a pole. The static friction coefficient is given as 0.2, with specific dimensions provided. Participants note that the initial solution is incorrect and emphasize the importance of symmetry in the forces acting on the hanger. There is a consensus that the problem can be approached using basic static principles, despite the instructor's suggestion that it is complex. Overall, the conversation highlights the challenge of applying static friction concepts in this scenario.
Femme_physics
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Homework Statement



What's the max weight, P, you can hang on the hanger's arm, when the hanger arm is attached to a pole with the help of two friction forces at point A and B.

http://img543.imageshack.us/img543/8466/maxwqeight.jpg


Homework Equations



Static friction coeffecient = 0.2
L = 0.5 [m]
d = 0.1 [m]

The Attempt at a Solution



Attached here... I didn't use all the equations but I wrote them anyway
 

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Dory: Nice work. Your current answer is incorrect. Hint 1: By symmetry, Fsb = Fsa. Now you have three unknowns, and three equations. Hint 2: Fs does not necessarily equal mus*N. Try again.
 
Thanks for replying, nvn! I was actually told by my lecturer yesterday that this question is actualy super hard since there is an angle between to two Na's and he's only going to teach it after kinematics...from some reason he decided to put it in the exercise book to "challenge us" but he never told us it's super hard and takes a lot of thought... I personally thought it seems easy and can be solved with basic static rules... but I guess I'm wrong?.
 
Femme_physics: You are right; it is solved with statics.
 
Ah...then peculiar why would he say it's so complicated when it's not. I'll try again later.

I like your usage of my new nickname, nvn :) though annoyingly longer, at least I don't sound like a Tolkien's dwarf.
 
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