Civil Engineering - UPSC Civil Service Exam Questions - Discussion

In the figure shows two blocks of equal weights designated as W₁ and W₂ connected together by a rod and resting on an inclined plane whose angle α can be varied. The coefficients of friction between the blocks and the surface of the plane are μ₁ = 0.2 and μ₂ = 0.3. The value of angle α at which the slipping will commence is given by