since you are in meters with an initial velocity of 0 m/sec then the equation is
h(t)=-9.8t^2 + 54
then how long to hit ground: h=0 on the ground so -9.8t^2 + 54 = 0
-9.8t^2 = -54
t^2 = 5.51
t = 2.35 seconds (note, even though it is t^2 you don't consider -2.35 also since time cannot be negative)
how fast were they going? 9.8 m/s^2 (2.35 seconds) = 23.03 m/sec downward