Review Problem. Sir Lost-a-Lot dons his armor and sets out fromthe castle on his trusty steed in his quest to improvecommunication between damsels and dragons (Fig. P12.20).Unfortunately his squire lowered the draw bridge too far andfinally stopped it 20.0° below the horizontal. Lost-a-Lot and hishorse stop when their combined center of mass is 1.00 m from theend of the bridge. The uniform bridge is 9.50 m long and has a massof 2400 kg. The lift cable is attached to the bridge 5.00 m fromthe hinge at the castle end, and to a point on the castle wall 12.0m above the bridge. Lost-a-Lot's mass combined with his armor andsteed is 950 kg. Suddenly, the lift cable breaks! The hinge betweenthe castle wall and the bridge is frictionless, and the bridgeswings freely until it is vertical. Figure P12.20
(a) Find the angular acceleration of the bridge once it startsto move. rad/s2 (
b) Find the angular speed of the bridge when it strikes thevertical castle wall below the hinge. rad/s2
(c) Find the force exerted by the hinge on the bridgeimmediately after the cable breaks. R = ( i + j) kN
(d) Find the force exerted by the hinge on the bridgeimmediately before it strikes the castle wall.
