Tarzan $($mT$=86\mathrm{.}4$kgmT$=86\mathrm{.}4$kg$)$ swings down from a cliff and has a speed of$14\mathrm{.}9$m$/$s$14\mathrm{.}9$m$/$s just before he impacts Jane $($mJ$=51\mathrm{.}8$kgmJ$=51\mathrm{.}8$kg$)$