Sliding friction - example 1

Material point with mass m is on the slope. Slope is inclined by angle α. Between slope surface and material point exists static sliding friction described by factor μ. Subject of example is to find angle αmax in equilibrium position. Because acting lines of all forces cross in one point it will be two equations:
• first equilibrium equation for forces or components of forces in X axis direction
• second equilibrium equation for forces or components of forces in Y axis direction