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

If the coefficient of static friction at B is μs = 0.3, determine the largest angle

θ, and the minimum coefficient of static friction at A, so that the roller remains self-

locking, regardless of the magnitude of the force P applied to the belt. Neglect the weight

of the roller and neglect friction between belt and vertical surface.

2. Relevant equations

ƩM=0

ƩF_{x}=0

ƩF_{y}=0

F_{A}=μ_{A}N_{A}

F_{B}=μ_{B}N_{B}=0.3N_{B}

3. The attempt at a solution

I have attempted the solution quite a few times a couple of different ways. I keep getting stuck with variables that I can't solve for, so I have come to the conclusion that I am probably not going about it the right way. My first attempt, I took the moment about A, and then summed up the forces in the x and y directions, but wound up not being able to solve for θ or μ_{A}. I attached an attempt at a free body diagram, perhaps I don't have the friction forces going in the right direction? I would appreciate any help!

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# Friction, Statics, Finding maximum angle and minimum coefficient of friction

Can you offer guidance or do you also need help?

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