A Stone Is Dropped From The Top Of A Cliff. It Hits The Ground Below After 3.10 S. How High Is The Cliff?

You need the formula:  S = ut + 1/2 at^2
Where s = ditance
you = initial velocity
t= time
a= acceleration which is 9.8 for gravity
Now you = 0 because the stone has no initial velocity
t = 3.1s
The answer is:
S= 0 + 1/2 (9.8 * 9.61)
s = 47.08 meters
So the cliff is approx 47 meters high