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Homework Help: Phase reversal of reflections

  1. Jan 6, 2005 #1
    I know that waves on a string are inverted on reflection from a hard surface. How about light waves and sound waves?
  2. jcsd
  3. Jan 6, 2005 #2


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    I don't unserstand what u could possbly mean by 'inverted',but i can tell you that sound and light waves get a phase shift by [itex] \pi [/itex] radians on each reflection.

  4. Jan 6, 2005 #3

    Doc Al

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    Light reflecting from a material of higher index of refraction will get phase shifted by [itex]\pi[/itex] radians (thus "inverted"), but light reflecting from a material of lower index of refraction will not get phase shifted.

    Sound waves reflecting from a hard surface will get phase shifted by [itex]\pi[/itex] radians.
  5. Jan 7, 2005 #4
    Sorry I thought everyone would be familiar with the concept of a phase shift of pi radians as being "inverted"
    I guess this means that light reflected from a mirror or any object eg. an apple is phase shifted by pi radians?
  6. Jan 7, 2005 #5
    Exactly! :-)
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