1. The problem statement, all variables and given/known data Chapter 12, problem 34. An auditorium has organ pipes at the front and at the rear of the hall. Two identical pipes, one at the front and one at the back, have fundamental frequencies of 264.00 Hz at 20.0°C. During a performance, the organ pipes at the back of the hall are at 25.0°C, while those at the front are still at 20.0°C. What is the beat frequency when the two pipes sound simultaneously? Use 3 significant figures. 3. The attempt at a solution Basically, I am not sure whether to assume the organ pipes are closed at one end, and open at the other, or open at both ends. My textbook says it can be both... Anyways, what I was going to do was just take a ratio of the frequencies. f1 / f2 = (n1*v1/4L) / (n2*v2/4L) The only problem here is I have 2 unknowns. I don't know n2 or f2..