1. The problem statement, all variables and given/known data Once closed organ pipe has a length of 3.2 m. Frequency of the note played by this pipe is 27 Hz. When a second pipe is played at the same time, a 1.50 Hz beat note is heard. By how much is the second pipe too long? 2. Relevant equations ??? 3. The attempt at a solution I'm really lost on this problem. I was thinking Lb-La=1/2 of wavelength, but I don't think that's right. Any direction is appreciated. Thanks in advance.