The uniform $18m$ mast has a mass of $300kg$ and is hinged at its lower end to a fixed support at $O.$ If the winch $C$ develops a starting torque of $1300Nm,$ calculate the total force supported by the pin at $O$ as the mast begins to lift off its support at $B.$ Also find the corresponding angular acceleration of the mast. The cable at $A$ is horizontal, and the mass of the pulleys and winch is negligible. Refer FigQ$11$

$,$ Fig $Q11$

Motor Drum Dia $=1200mm$