A ball is swung in a circle with a radius of 2 meters. When the ball has moved along the arc a distance of 8.2 meters, through what angle did the ball rotate. Show how you got the answer

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.