Q$13)$ A $40\mathrm{.}0-$g rock is thrown up into the air with an initial speed of $6\mathrm{.}0$ m$/$s$.($a$)$ Using the"principle of mechanical energy conservation", $($a$)$ calculate the maximum height the rock reaches $($neglect air resistance$).($b$)$ determine the kinetic energy of the ball at the highest pQ$14)$