Useful use of the wave equation

[Apothem]

Homework Statement

Our teacher asked us to find a useful use of the wave equation, in which we must explain how the wave equation is used in the application we chose, in which will be a 2 minutes at max speech.

Homework Equations

Wave equation v=f*λ

The Attempt at a Solution

I have been looking around the internet but have had little luck, the uses I have found are either not useful or exciting, in which the teacher wants, or in too much detail. So I was wondering if any of you can give me some interesting uses of the wave equation.

 

[Apothem]

I have just found an interesting use, so no need for the question, this can be locked now, if that is how it works...