A length of organ pipe is closed at one end. If the speed of sound is 344 m/s, what length of pipe (in cm) is needed to obtain a fundamental frequency of 50 Hz?
A) 28
B) 86
C) 344
D) 172
E) 688

Question

Quizplus · Accepted Answer

The fundamental frequency for a closed organ pipe is given by:

f = v/4L

where v is the speed of sound and L is the length of the pipe.

Rearranging the formula to solve for L yields:

L = v/4f

Substituting in the given values:

L = 344 m/s / 4(50 Hz) = 0.43 m = 43 cm

Therefore, the length of pipe needed to obtain a fundamental frequency of 50 Hz is 43 cm or 0.43 m, which corresponds to answer choice D.

A Length of Organ Pipe Is Closed at One End