A rock thrown with speed $12\mathrm{.}0$ m$/$s and launch angle $30\mathrm{.}0$$\mathrm{ (}$above the horizontal$)$ travels a horizontal distance of d$=17\mathrm{.}5$ m before hitting the ground. From what height was the rock thrown? Use the value g$=9\mathrm{.}800$ m$/$s$2$ for the free$-$fall acceleration. Find the height yi from which the rock was launched.