Q.6 A ladder of mass m is leaning against a wall, as shown in the figure below. A mass M is hung from the middle of the ladder. The wall and the ground have a coefficient of friction. What is the value oof the angle a below which the ladder cannot remain in static equilibrium? IISc-2008] NNNI IRNR 2 24 (a) tan a =_ 1-u2 (b) cot a = m/M-u 24 (c) tan a M/m-u2 (d) cot a1-2 u2