Review Multiple$-$Concept Example $7$ in this chapter as an aid in solving this problem. 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 $0\mathrm{.}672$ m$.$ At one point on this circle, the ball has an angular acceleration of $64\mathrm{.}7$ rad$/$s$2$ and an angular speed of $15\mathrm{.}8$ 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.