An organ pipe open at both ends has a length of 0.80 m. If the velocity of sound in air is 340 m/s, what is the frequency of the second harmonic of this pipe?
A) 213 Hz
B) 850 Hz
C) 425 Hz
D) 638 Hz

Question

Quizplus · Accepted Answer

The second harmonic of an open pipe is twice the fundamental frequency. The fundamental frequency is given by $ f_1 = \frac{v}{2L} $, where $ v = 340 \, \text{m/s} $ and $ L = 0.80 \, \text{m} $. So, $ f_1 = \frac{340}{2 \times 0.80} = 212.5 \, \text{Hz} $. The second harmonic is $ 2 \times 212.5 = 425 \, \text{Hz} $.

An Organ Pipe Open at Both Ends Has a Length