In a fast-pitch softball game the pitcher is impressive to watch, as she delivers a pitch by rapidly whirling her arm around so that the ball in her hand moves in a circle. In one instance, the radius of the circle is 0.678 m. At one point on this circle, the ball has an angular acceleration of 68.9 rad/s2 and an angular speed of 13.5 rad/s.
(a) Find the magnitude of the total acceleration (centripetal plus tangential) of the ball.
(b) Determine the angle of the total acceleration relative to the radial direction.