1. The problem statement, all variables and given/known data A uniform ladder of mass m and length L leans at an angle of theta against a frictionless wall. If the coefficient of static friction between the ladder and the ground is mu, determine a formula for the minimum angle at which the ladder will not slip. I have added my own additional information in red. 2. Relevant equations various equations perhaps. mu= Ffr/FN Ffr is friction force. FW is force by the wall 3. The attempt at a solution http://img171.imageshack.us/img171/1830/s8sv4.jpg this is what I have done. I took my ref point at the top of the ladder. (FN)(Lcostheta) + (Ffr)(Lsintheta) = (mass*g)(L/2 costheta) I don't know if this approach is correct. I doubt it. Can someone give me head start here?...I have been stuck on this problem for a while now. How do I set this up? Thanks.