You drop a rock(from rest) into a well. You hear the rock hit the bottom 3.15 seconds after you dropped it. How deep is the well? Do not ignore the time for sound to travel back up to your ear.
Velocity of sound = 343 m/s (constant), g = 9.8 m/s^2
The equations I have to use are:
1. V = Vo + a(t)
2. deltaX = Vo + 1/2(a)(t^2)
3. V^2 = Vo^2 + 2(a)(deltaX)
4. deltaX = 1/2(Vo + V)(t)
The Attempt at a Solution
I tried using equation 4 and got: 1/2(0+343)(3.15) = 540.225m
I have no idea if this is right or not. The entire portion involving sound is throwing me off. Where am I actually suppose to use the speed of the sound at?