In the situation described in Problem 20 and illustrated in Figure P12.20, the lift cable suddenly breaks! The hinge between the castle wall and the bridge is frictionless, and the bridge swings freely until it is vertical.
(a) Find the angular acceleration of the bridge once it starts to move.
(b) Find the angular speed of the bridge when it strikes the vertical castle wall below the hinge.
(c) Find the force exerted by the hinge on the bridge immediately after the cable breaks.
(d) Find the force exerted by the hinge on the bridge immediately before it strikes the castle wall.