An attacker at the base of a castle wall $4\mathrm{.}00$ m high throws a rock straight up with speed 0$8\mathrm{.}10$ m/$/$s from a height of $1\mathrm{.}60$ m above the ground.

 A)$)$What is its speed at the top?

 B)$)$ Find the change in speed of a rock thrown straight down from the top of the wall at an initial speed of $8\mathrm{.}10$ m/$/$s and moving between the same two points.

 C)$)$ Does the change in speed of the downward−$-$moving rock agree with the magnitude of the speed change of the rock moving upward between the same elevations?