1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Standing waves in a pipe

  1. Oct 10, 2014 #1
    1. The problem statement, all variables and given/known data
    What is the base frequency of a 20 cm pipe which is open on both ends.
    Again but closed on one end.

    2. Relevant equations
    u=velocity, [itex]\lambda[/itex]=wave length: [itex]\lambda=\frac{u}{f}[/itex]
    Velocity in air=348[m/sec]

    3. The attempt at a solution
    I understand these are standing waves in air.
    In an open end there is a peak, so the first wavelength is [itex]\lambda=2\cdot 20=40[cm][/itex]
    ##0.4=\frac{348}{f_1}\rightarrow f_1=870[Hz]##
    The answer should be 1140[Hz]
    In the closed on one end condition, in the open end there is a peak and in the closed end a node, so the wavelength is [itex]\lambda=4\cdot 20=80[cm][/itex]
    ##0.8=\frac{348}{f_1}\rightarrow f_1=435[Hz]##
    The answer should be 570[Hz]
    Both answers differ from the right ones by the same factor
  2. jcsd
  3. Oct 11, 2014 #2


    User Avatar

    Staff: Mentor

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted