A few sound problems

  1. 1. The problem statement, all variables and given/known data
    1. An unfingered guitar string is 0.70 m long and is tuned to play E above middle C (330 Hz). How far from the end of this string must the finger be placed to play A above middle C (440 Hz)?

    2. An organ is in tune at 20 degrees C. By what fraction will the frequency be off at 0 degrees C?

    2. Relevant equations

    3. The attempt at a solution

    1. I used the v=(freq)(wavelength) equation:
    v = (330)(0.70) = 231 m/s
    Then i plugged in 231 to figure out the distance for 440 Hz:
    (231 m/s) = (440)x
    x=.525 m
    I'm not sure if my method is right, so please check that! thanks

    2. Not sure about this one

    Thanks for the help
  2. jcsd
  3. I think that's right.

    For the second part,
    [tex]v=\sqrt{\frac{\gamma RT}{M}}[/tex] The temperature should be in Kelvin. Since there is no change in the gas, [tex]\frac{\gamma R}{M}[/tex] are constant, and so the speed of sound varies with the square root of temperature. That should help you out.
Know someone interested in this topic? Share this thead via email, Google+, Twitter, or Facebook

Have something to add?
Similar discussions for: A few sound problems