Be sure to review Example $2\mathrm{.}8($Section $2\mathrm{.}5)$ before attempting

these problems.

Part A

You throw a rock straight up from the edge of a cliff. It leaves your hand at time $t=0$ moving at $12\mathrm{.}0\frac{m}{s}.$ Air resistance can be neglected. Find both times at which

the rock is $4\mathrm{.}00m$ above where it left your hand.

Enter your answers in ascending order separated by a comma. Express your answer in seconds.

$\sqrt[]{,A}$

$?$

$t=$

$s$