1. The problem statement, all variables and given/known data #24 https://aapt.org/physicsteam/2010/upload/2009_F-maSolutions.pdf 2. Relevant equations T = rfsinθ 3. The attempt at a solution FBD: Axes: (along the incline is x), perpendicular to that is y: Down: mgcosθ Up: N Right: mgsinθ Left: Ff (friction) If the box is to tip over, it will rotate around one vertex, namely the bottom right. We choose that as PoR and do net torque. (b/2)mgcosθ = Torque, isn't that the only torque? Or is it: b/2mgcosθ = aμmgcosθ If the box isn't slipping down the plane, then Ff = mgsinθ μmgcosθ = mgsinθ tanθ = μ I don't really know what to do beyond that.