A 20.0 cm long organ pipe is filled with air and is open at one end and closed at the other.The velocity of sound in air at 0$^{\circ}$C is 331 m/s.What is the frequency of the third mode?
A) 2,070 Hz
B) 2,190 Hz
C) 2,320 Hz
D) 2,450 Hz
E) 2,680 Hz

Question

Quizplus · Accepted Answer

The third mode in a pipe open at one end and closed at the other is the fifth harmonic. The formula for the frequency of the nth harmonic is $ f_n = \frac{n \cdot v}{4L} $. For the fifth harmonic (n=5), with L = 0.2 m and v = 331 m/s, the frequency is $ f_5 = \frac{5 \cdot 331}{4 \cdot 0.2} = 2,070 $ Hz.

A 200 Cm Long Organ Pipe Is Filled with Air and and Is