Describe an experiment that would use a pipe to determine the speed of sound in helium?

Question

Include a labeled diagram to back up your description. 

Answer 1

This forum does not accommodate diagrams.

 

Suppose you have a pipe of length L open at one end and closed at the other, immersed in helium.  With an adjustable tuning fork at the open end of the pipe, initiate vibration of the helium gas in the pipe until you establish the first harmonic.  Record the frequency of the tuning fork.  Call it f.  With a pipe open at one end and closed at the other, the first harmonic will have 1/4 of a wavelength inside the pipe, so

 

λ/4 = L ⇒

 

λ = 4L

 

Get the speed of sound from

 

v = λf = 4Lf