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

Two loudspeakers are placed beside each other and produce sound of the same intensity at the position of a listener. One speaker produces a low note of 40 Hz and the other produces a high note of 2560 Hz. What is the ratio of the maximum displacements of the speakers vibrating cones?

**2. Relevant equations**

1) [itex]I[/itex]=P/4piR^2

2) I=1/2BωkA^2

3) I=1/2[itex]\sqrt{ρB}[/itex]ω^2A^2

**3. The attempt at a solution**

I understand that I am supposed to use equation 3 for both frequencies and set them equal to each other to come up with a ratio. I just don’t understand how equation 3 is derived from equation 1, or how equation 2 is derived from equation 1 for that matter. If I could see how to manipulate these equations I would understand this type of problem much better. (The only equation I am given on my equation sheet is the first one).

http://ift.tt/1gDEKL1