I can then increase the angle of inclination until this block just starts to slide. At the moment it starts to slide, I can calculate both the normal force (pushing the plane against the object ...

Of course, we already have an expression for the normal force. Putting this all together, I get: Combining this with the lean angle calculation: So what would be the coefficient of static friction ...

the shear force will overcome the normal force of gravity. This is usually the moment the materials start sliding down the slope and the angle of repose is reached. This might sound like a very ...