You throw a ball off a cliff on some distant planet at tt $=0.$ Its motion is described by this position vector r$=100$mj$^+(10$m$/$s$)$ti$^(2\mathrm{.}8$m$/$s$2)$t$2$j$^$r$=100$mj$^+(10$m$/$s$)$ti$^(2\mathrm{.}8$m$/$s$2)$t$2$j$^.$ What is the acceleration of the ball after you throw it$?$

$-5\mathrm{.}6$m$/$s$2$j$^$m$/$s$2$j$^-2\mathrm{.}8$m$/$s$2$j$^$m$/$s$2$j$^+5\mathrm{.}6$m$/$s$2$j$^$m$/$s$2$j$^$Zero