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Speed of refracted waves in different mediums

  1. May 24, 2009 #1
    1. The problem statement, all variables and given/known data
    two vibrating sources emit waves in the same elastic medium. the first source has a frequency of 25 hz, while the frequency of the second source is 75hz. waves from the first source have a wavelength of 6.9 m. they reflect from a barrier back into the original medium, with an angle of relfection of 25 degrees. waves from the second source refreact into a different medium with an angle of incidence of 35 degrees. the speed of the refracted waves is observed to be 96 m/s.




    2. Relevant equations
    wat is the is the speed of the reflected waves from the first source in the orignal medium?



    3. The attempt at a solution
    you cannot tell since it has most likely changed speed after refraction?


    Im doing a correspondance course and learning out of a book is retarded.
    Can someone explain this to me please?
     
  2. jcsd
  3. May 25, 2009 #2

    Redbelly98

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    Re: refraction?

    Welcome to Physics Forums. :smile:

    There seems to be a lot of unnecessary information given here. But they do tell us what the first wave's frequency and wavelength are. What equation can you use to get the speed?
     
    Last edited: May 26, 2009
  4. May 25, 2009 #3
    Re: refraction?

    Darn it. I posted the right problem but the wrong question. the right question is...

    what is the speed of the waves from the second source in the original medium?
     
  5. May 25, 2009 #4

    Redbelly98

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    Re: refraction?

    It appears there is not enough information to solve this problem, unless we assume the same speed for the two frequencies.

    I fail to see the relevance of the 25 degree angle of reflection for the first wave.

    Was there a figure accompanying this problem? Perhaps it contains other information, or a better description of the situation.
     
  6. May 25, 2009 #5
    Re: refraction?

    Thats all the information given.
    No figures.

    Its got me all confused.
     
  7. May 26, 2009 #6

    Redbelly98

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    Re: refraction?

    It seems we should assume the two wave speeds are the same, which is generally true anyway. In that case, my comment in post #2 applies.
     
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