A ball of mass .5 kg moves perpendicular to the door by the speed of 10 m/s. The door has a mass of 3 kg and a width of 2 m and is hinged about one end. The moment of inertia of a bar rotated about its end is 1/3 Ml^2. The ball strikes the end of the door opposite hinge and stops moving. What is the angular speed of the door after the collision?