Problem 12.37 Part A At T = 14 C, how long (length) must an open organ pipe be t
ID: 1475876 • Letter: P
Question
Problem 12.37
Part A
At T = 14 C, how long (length) must an open organ pipe be to have a fundamental frequency of 349 Hz ? The speed of sound in air is v(331+0.60T)m/s, where T is the temperature in C.
Express your answer to three significant figures and include the appropriate units.
Part B
If this pipe is filled with helium at 20C and 1 atm, what is its fundamental frequency? The speed of sound in helium is 1005 m/s.
Express your answer to three significant figures and include the appropriate units.
Explanation / Answer
A)
T = 14 oC
Vsound = 331+0.60T = 331+0.60*14 = 339.4 m/s
f = Vsound / 2*L
349 = 339.4 / (2*L)
L = 0.486 m
Answer: 0.486 m
B)
f = Vsound / 2*L
= 1005 / (2*0.49)
f = 1025.5 Hz
Answer: 1030 Hz in 3 significant figure