The Attempt at a Solution
First, I drew the FBD for the system, one horizontal force at A, one force perpendicular to the beam at B, and the weight.
Writing out the equilibrium equations:
The sum of forces in the y direction should be 0, so I have the equation:
Nb cos(θ) - W = 0, which can be rearranged for Nb later on.
Then I took the moment about point A:
Nb (a/cosθ) - Wcosθ (L/2) = 0
Eventually, it simplifies out to cos^-1 ( (2a/L) ^(1/3) ) = θ
I don't think I got the right answer, but can someone help me identify my error? Thank you in advance.