How to find distance using sound waves

[PhizKid]

Homework Statement

Homework Equations

x = (v_0)^2 - (1/2)gt^2

The Attempt at a Solution

Well, since the stone is dropped from rest, and the down direction is negative, the displacement is:

x = -(1/2)gt^2
x = -(1/2)(9.8 m/s^2)(3.00 s)^2
x = -44.1 m.

But this is incorrect and I don't recall any equation to express distance using sound waves given only the time since there isn't any other information we can assume from the free-fall I think.

 

[tms]

Sound has a finite speed; you can look up its value. The time between dropping the stone and hearing the splash is the time the stone takes to fall plus the time the sound takes to reach your ears.