I do not understand what is meant in this question: An open organ pipe has a fundamental frequency of 430 Hz. A closed organ pipe has a fundamental frequency that is the second harmonic of the open organ pipe. What are the lengths of the two pipes? Does the bolded part mean that the fundamental frequency of the closed pipe is twice that of the open pipe? (since 2*fundamental frequency = second harmonic frequency) Something about the wording is tripping me up here. If so, how would I find the length only knowing frequencies (not velocities or wavelengths)? thanks!