Problem in words

Samantha was on a roller coaster that was 90ft high and fell at the velocity of -10 ft/sec before turning 10ft from the ground. While she was going down her keys fell down from the same height  as the roller coaster. how long will it take for the keys to hit the ground? How long will it take for Samantha's roller coaster to turn at 10ft from the ground? will the times be close or will they be a great difference?

The Formula and given in formation

h=-16t² + vt + s                    h= -16t²+ s

h = 10                                 h = 0
v = -10                                s = 90
s = 90                                 t = t
t = t


 

y=x
y=-x
y=x²
y=-x²
y=x³
y=-x³
y=|x|
y=-|x|