Posted by **Kristina** on Friday, February 11, 2011 at 3:12pm.

At a height of 15 meters above the surface of a lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.150 s later. The air and water temperatures are 20°C. How deep is the lake?

- Physics -
**Damon**, Friday, February 11, 2011 at 3:50pm
look up speed of sound in water at 20C

call it Cw

look up speed of sound in air at 20C

call it Ca

then distance in water = 2d

distance in air = 30

time in water = t

time in air = (.15 -t)

then

time in air = 30/Ca = .15 - t

solve for t

then

Cw t = 2 d

- Physics -
**SraJMcGin**, Friday, February 11, 2011 at 4:50pm
Try some of the Physics Tutorials:

http://search.yahoo.com/search?fr=mcafee&p=Physics+tutorial

Sra

## Answer This Question

## Related Questions

- AP Physics - At a height of 5 meters above the surface of a freshwater lake, a ...
- physics - A hiker determines the length of a lake by listening for the echo of ...
- physics - An airplane wants to drop a load of fish inot a small lake in the ...
- math - Surfact of A lake is 31 feet above the surface of B lake. B lake is half ...
- arithmetic - a flower floats on the surface of lake water. its level above the ...
- physics - A hiker determines the length of a lake by listening for the echo of ...
- physics - a boy stands on a cliff overlooking a lake below. He throws a rock at ...
- PHYSICS - Waves - Can someone tell me how to get the answer to this question? ...
- Math - Sadiq dropped his watch into a lake. The depth of the lake is 5 meters. ...
- Physics - The maximum depth of Lake Baikal, in Russia, is 1637 m, making it the ...

More Related Questions