A uniform cubical block of mass M and side length L is lying on the edge of a rough table with `(1)/(4) th` of its edge overhanging. When a small block of mass m is placed on its top surface at the right edge (see fig.), the cube is on verge of toppling. The block of mass m is given a sharp horizontal impulse so that it acquires a velocity towards B. The small block moves on the top surface and falls on the other side. What is maximum coefficient of friction between the small block and the cube so that the cube does not rotate as the block moves over it. Assume that the friction between the cube and the table is large enough to prevent sliding of the cube on the table.
