I am not good at math at all, I install well pumps and sometimes need too know how deep a well is. So, verry primitivley I drop a pebble down the well and very roughly judge the depth. I would be very thankfull if one of you math savvy people out there could tell me a formula to calculate depth (in feet) using the time it takes a small pebble too reach the bottom (in seconds). If any of this is unclear please email me at (e-mail address removed). thank you.

This message has been edited. Last edited by: DorianGreyed,

A falling object accelerates at the rate of 32ft per second. Therefore at the instant you release it, the pebble is at zero feet per second and at the end of the first second it has gone from zero to 32 fps,(average speed 16fps for 1 second) so it has fallen 16 feet.the formula to use would be d=16t^2. If it is 2 seconds it would be 16x2x2=64feet. In 3 seconds 16x3x3=144 feet, and so on. Of course the distance would be a little less than the calculated since there is going to be some air resistance.