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Homework Help: Where will the image of the candle be formed?

  1. Feb 28, 2010 #1
    1. The problem statement, all variables and given/known data

    A water tank is 4 meters deep. A candle flame is kept 6 metres above the level of the water. Mu for water is 4/3. Where will the image of the candle be formed?

    2. Relevant equations



    3. The attempt at a solution

    I need a few clues to proceed. If I consider refraction at the water surface the image will be formed above the candle flame. The answer given in the book is 6 metres below the water level.
     
  2. jcsd
  3. Feb 28, 2010 #2

    tiny-tim

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    Hi kihr! :wink:
    I think they must mean reflection, not refraction. :smile:
     
  4. Feb 28, 2010 #3

    ehild

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    Re: Optics

    It depends on the position of the observer. An observer above the water sees the mirror image of the candle. An observer looking up would see the candle flame above the real one.

    ehild
     
  5. Feb 28, 2010 #4
    Re: Optics

    If we consider the surface of water as a mirror the answer is simple. But then what is the significance of giving the depth of the tank and the refractive index of water in this problem? This is what has confused me. Could you throw some light on this please?
     
  6. Feb 28, 2010 #5

    ehild

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    Re: Optics

    I can not read the mind of other people. Maybe, there are more questions in your book, concerning the same set-up. Sometimes more data are given in a problem than necessary so as the student should choose which are relevant.

    ehild
     
  7. Feb 28, 2010 #6
    Re: Optics

    Thanks. I think the whole idea might have been to confuse the student!!
     
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