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Homework Help: Black oil - colours?

  1. Jan 24, 2010 #1
    Black oil - colours????

    1. How does black oil on a windscreen appear to be all colours???



    2. Is it because black absorbs all frequencies of light?



    3. i'm not sure how to answer this question can anyone help?
     
  2. jcsd
  3. Jan 24, 2010 #2

    mgb_phys

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    Re: Black oil - colours????

    It's nothing to do with the color of the oil
    hint - look up interference
     
  4. Jan 25, 2010 #3
    Re: Black oil - colours????

    does this make sense?

    the oil it acts like a thin film. The light of different wavelengths (colors) refract and reflect at different angles, and the reflections add up or cancel each other out by superposition depending on the wavelength and angle.
     
  5. Jan 25, 2010 #4

    mgb_phys

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    Re: Black oil - colours????

    Yes - but do you understand that or did you just cat&paste it from wiki?
     
  6. Jan 25, 2010 #5
    Re: Black oil - colours????

    its an explanation someone gave me today but im still not sure i understand it completely.
     
  7. Jan 25, 2010 #6

    DaveC426913

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    Re: Black oil - colours????

    You may have better luck (because it is a more common) looking into rainbows in soap bubbles. Same principle, but much better hits when searching.
     
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