One fourth length of a Uniform Rod of mass $m$ and length $x$ is placed on rough horizontal surface and it is held stationary by means of a light thread as shown in the figure. The thread is brunt and the rod starts rotating about the edge, the co-efficient of friction of the surface is $μ$. Determine the angle between the rod and the horizontal surface at which the rod is about to slip on the edge.
I am confused on 'How the friction force would act?'or basically the FBD (Free Body Diagram).