Part A A small ball is attached to the lower end of a 0.800-m-long string, and the other end of the string is tied to a horizontal rod. The string makes a constant angle of 61.0 with the vertical as the ball moves at a If it takes the ball 1.25 s to complete one revolution, what is the magnitude of the radial acceleration of the ball? constant speed in a horizontal circle. Express your answer with the appropriate units. HA ? arad = Value Units