# Properties of Sound

1. Mar 15, 2007

### tdk

1. The problem statement, all variables and given/known data

"A rifle is fired in a valley with parallel vertical walls. The echo from one wall is heard 2.0 s after the rifle was fired. The echo from the other wall is heard 2.0 s after the first echo. How wide is the valley?

2. Relevant equations

I dont know any relevant equations. v=wavelength x frequency? Do I have to convert something into decibels?

3. The attempt at a solution

time=2 s
distance=?
.

Last edited by a moderator: Mar 16, 2007
2. Mar 15, 2007

### denverdoc

No nothing that cpplex--just that the speed of sound is 340meters/sec. Hint: to avoid simple errors, draw a picture of the reflecting sound waves so as to include all the distances.

3. Mar 15, 2007

### tdk

But I dont understand how you apply the speed of sound to the problem. Do you multiply it by 2?.

Last edited by a moderator: Mar 16, 2007
4. Mar 15, 2007

### denverdoc

know leave the speed alone and as i suggested draw a diagram. In this case, try to isolate the time requires for sound to span the valley. Hint its 1/2 the sum...

5. Mar 15, 2007

### tdk

alright pugfug, I told you I unclicked the "Automatically parse links in text" and thats why the link wasnt clickable anymore. And now everytime I post I unclick it so it doesnt come up as a link. Do you understand that? I dont get why I cant post here if the link isnt even clickable, whats the harm?

Thanks Denverdoc I'll try that.

Last edited by a moderator: Mar 16, 2007