A 25.0 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 fifth mode?
A) 1,550 Hz
B) 1,750 Hz
C) 2,320 Hz
D) 2,720 Hz
E) 3,170 Hz

Question

Quizplus · Accepted Answer

The fundamental frequency of an open-closed organ pipe can be calculated as:
f = v/4L, where v is the velocity of sound in air and L is the length of the pipe.
For the fifth mode, there are five antinodes (points of maximum amplitude) and four nodes (points of zero amplitude) along the length of the pipe. 
The frequency of the fifth mode can be calculated as:
f5 = 5f = 5v/4L
Substituting the given values, we get:
f5 = 5 x 331/(4 x 0.25) = 2,320 Hz
Therefore, the answer is C.

A 250 Cm Long Organ Pipe Is Filled with Air and and Is