A uniform rod of length 2a runs from A to B and has mass km kg. The rod is freely hinged at the point A and at the point B,

it is freely hinged to another uniform rod of length 2a and mass m. Both rods are in equilibrium with the first rod horizontal and the second inclined at angle 0 to the vertical, with its unhinged end in contact with the rough floor. The coefficient of friction between the rod and the floor is u. What is the minimum value that u can take in terms of k and 0?