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Speed of Sound in Air as a Function of Temperature

  1. Dec 12, 2014 #1
    Hi, guys! :) I do hope I am posting on the right thread here.

    So anyways, I'm looking into a certain topic: "Speed of Sound in Air as a Function of Temperature".

    Any thoughts on how I could do this experimentally?

    Warm regards,
    Paulene :)
     
  2. jcsd
  3. Dec 12, 2014 #2

    Doug Huffman

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    Set up a resonant air column and vary the air temperature to effect the resonant frequency.
     
  4. Dec 12, 2014 #3
    Wow! I didn't expect to get an immediate reply. Thank you, Sir.

    Would you be so kind to elaborate a little further as to how I may be able to set up an air column? :(
     
  5. Dec 12, 2014 #4

    Doug Huffman

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    A whistle.
     
  6. Dec 12, 2014 #5
    My Physics supervisor asked me to look into the topic for my Physics Extended Essay. I was thinking of maybe relating it with Airplanes and how they possibly break sound barriers? If that makes any sense???
     
  7. Dec 12, 2014 #6

    Doug Huffman

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    Airplanes near the speed of sound are resistant to experiment.

    Do you know the effect of temperature on the speed of sound in theory?
     
  8. Dec 12, 2014 #7
    Awwww. So supposing I disregard that mentality and follow through with your suggested experiment, what research question could I formulate, Sir?
     
  9. Dec 12, 2014 #8

    Doug Huffman

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    How does resonant frequency vary as temperature of air column? First do it qualitatively as you learn your equipment, heating causes rise or decline ins resonant. Acquire instruments for temperature and audio frequency and refine.
     
  10. Dec 12, 2014 #9
    Oh, okay. Thank you very much, sir! I have a meeting with my Supervisor this Sunday and I have yet to find out what he thinks about it. If you've got any other suggestions, please let me know. It doesn't really have to be related to this topic, just something that's not too simple nor complex enough to do an experiment on.

    Truly appreciate all your help.

    Warm regards,
    Paulene
     
  11. Dec 12, 2014 #10
    And also, I've looked into the speed of sound with regards to the temperature. The lower the temperature is, the faster the travel of speed of sound.
     
  12. Dec 12, 2014 #11

    boneh3ad

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    You made a mistake somewhere, then.
     
  13. Dec 12, 2014 #12
    Wait, what?
     
  14. Dec 12, 2014 #13

    boneh3ad

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    The speed of sound in a gas that can be treated as a perfect gas (like air) has a well-known relationship with temperature, and it is not an inverse relationship.
     
  15. Dec 12, 2014 #14
    hmmmmmmmmmmmmmmmmmmmm
     
  16. Dec 12, 2014 #15

    boneh3ad

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  17. Dec 12, 2014 #16
    Ohhh. That explains a lot. Thanks :)

    Have you got suggestions on how I'd be able to do this experimentally as opposed to the one suggested above?
     
  18. Dec 12, 2014 #17

    boneh3ad

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    I mean, there are any number of ways depending on what equipment you have available and how accurate you need to be. You could even do something simple like put a sound source and a pressure transducer/microphone in a foam-lined box (for acoustic insulation) a known distance apart and then record how long it takes for the microphone to register a sound you tell the source to make.
     
  19. Dec 12, 2014 #18

    sophiecentaur

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    If you have a source of audio tones and a microphone, you can find the resonant frequencies of an open pipe, immersed vertically in a water bath (to change the temperature).
    If you look at the formula in this link , you can see that the change over the temperature range obtainable in a water bath is not great so you may need to be careful with your measurements.
    Google 'Open Pipe Resonance' for the background knowledge. Hyper physics is your friend in this sort of problem.
     
  20. Dec 12, 2014 #19

    Doug Huffman

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    The box brings up a story. Sonar location needs an accurate measure of the speed of sound in water that has more parameters than in air. So a box is used with an ultrasonic transmitter and receiver timing the travel of pulses through water continually sampled by an auxiliary system. Some numbers from that part of my life; speed of sound in air is about 1000 fps, in water about 5000 fps and in steel about 15000 fps - as I recall.
     
  21. Dec 12, 2014 #20

    Danger

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    That suddenly made me think of something that never crossed my mind before. If something could manage to go fast enough under water, would there be a "sonic boom" similar to what happens in air? If so, how would it propagate?
    The main reason that I'm curious about it is because of the still-untraced massively loud "booms" from underwater (somewhere in or near Asia, I think) that don't match any other known seismic signals. Maybe a small but extraordinarily powerful sea-floor volcanic eruption could spit out a rock that fast?
     
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