Static friction is my answer correct?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
4 replies · 2K views
Femme_physics
Gold Member
Messages
2,548
Reaction score
1

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
 

Attachments

  • equalll.jpg
    equalll.jpg
    22.8 KB · Views: 518
Last edited by a moderator:
on Phys.org
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?.
 
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.