A thin, uniform, metal bar, 3m long and weighing 85 N, is hanging vertically from the ceiling by a frictionless pivot. Suddenly it is struck 1.3m below the ceiling by a small 4-kg ball, initially traveling horizontally at 14 m/s. The ball rebounds in the opposite direction with a speed of 7 m/s.
Find the angular speed of the bar just after the collision.