# Pebble falling into well

1. Jan 16, 2005

### blair2707

A pebble is dropped into a well. It takes 15 seconds for the sound of the splash to be heard. If the speed of sound is 343 m/s how deep is the well?

2. Jan 16, 2005

### Curious3141

There was another recent problem in a similiar vein. Can you try searching for it ?

This problem involves solving a quadratic equation. Do you know how to do those ?

3. Jan 16, 2005

### dextercioby

Since it's posted in the College section,it would be a shame if he didn't... :tongue2:

Daniel.

4. Jan 16, 2005

### Curious3141

True. It seems strange that there's such a high degree of overlap between the standard of problems posed in the other forum and this one.

5. Jan 16, 2005

### blair2707

Hey guys I posted this hoping for some help not attitude towards my question, isn't that what this forum is for???

6. Jan 16, 2005

### brewnog

7. Jan 16, 2005

### dextercioby

This forum is indeed to help.Did u read the "sticky" on top of the list of threads??

Daniel.

PS.We won't do the problems for you...

8. Jan 17, 2005

### andye

help

hint: 15 seconds is the time it takes for the pebble to fall + the time it takes for the sound to travel back up the well. Since t is a known in the equation, and the pebble falls the same height the splashing sound travels, the solution is obtainable through a quadratic function of x. You know t=15, a=g=9.8, v=343...