$2\mathrm{.}22)$An Australian emu is running due north in a straight line at a speed of $13\mathrm{.}0$ m$/$s and slows down to a speed of $9\mathrm{.}40$ m$/$s in $4\mathrm{.}10$ s$.($a$)$ What is the magnitude and direction of the bird$$s acceleration? $($b$)$ Assuming that the acceleration remains the same, what is the bird$$s velocity after an additional $2\mathrm{.}50$ s has elapsed?