Question

an aluminum pipe .655 m long at 20 deg celsius and open on both ends, is used as a flute. the pipe is cooled to a low temperature, but then filled with air at 20 deg celsius as soon as you start to play it. after that by how much does its fundamental frequency change as the metal rises in temperature from 5 deg celsius to 20 deg celsius?

Answer 1

The pipe is open at both ends. Therefore, its fundamental frequency is given by

..........(1), v is velocity of sound and L is length of tube.

Speed of sound at Celsius = 331 m/s

Speed of sound at 5⁰ Celsius   

m/s

m/s

Speed of sound at 20⁰ C   

m/s

Now, fundamental frequency at 5⁰ C, from equation (1)

Hz

Now, fundamental frequency at 20⁰ C,

Hz

Therefore, change in fundamental frequency,

Hz

Therefore, 6.87 Hz is the required fundamental frequency change.