A rough uniform rod, of length 2a, is placed on a rough table at right angles to its edge; if its centre of gravity be initially at a distance b beyond the edge, show that the rod will begin to slide when it has turned through an µ₂² angle tan-1. a²+ 9b²' where µ is the coefficient of friction.

A rough uniform rod, of length 2a, is placed on a rough table at right angles to its edge; if its centre of gravity be initially at a distance b beyond the edge, show that the rod will begin to slide when it has turned through an µ₂² angle tan-1. a²+ 9b²' where µ is the coefficient of friction.