Can someone tell me how to get the answer to this question? Just a formula would be great. It's on my physics study guide for my unit test.

Question

It takes 2.30 s for an echo to come back from a sound wave sent to the bottom of a 25 degree C lake. How deep is the lake at this location? (Answer, 3433.9 m)

Answer 1

D = = V*t = 343m/s * (2.3/2) = 394.5 m.

NOTE: If your answer is correct, the lake is 0ver 2 miles deep.