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Homework Help: I know this is probably a really dumb question, but I still don't get it. Don't laugh

  1. Jan 22, 2005 #1
    Chris and Pat are enjoying a sunny day by a small lake. As they watch the sunlight hit the water, rocks, and other objects, they start talking about what they have learned about light, sound and waves in science class.
    Chris and Pat observe that the sunlight hitting their blanket is reflecting in many different directions. Which statement best explains their observation?

    A. Light reflects off in all directions because the surface has very small bumps and valleys

    B. The light must be coming from many directions for the light to reflect off in many directions

    C. The smoothness or roughness of the surface makes no difference; light always reflects in many directions
  2. jcsd
  3. Jan 22, 2005 #2

    Andrew Mason

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    You can use the process of elimination here. It cannot be B because the light reflecting off other surfaces is a tiny fraction of that coming directly from the sun. So the dominant source of light is the sun which all comes from one direction. It cannot be C because we know that light reflection depends on the surface. A smooth surface reflects light in the same way. So the answer must be A, which makes sense: light reflects at the same angle that the incident light makes to a line tangent to the reflecting surface.

  4. Jan 22, 2005 #3


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    "B" and "C" are partly right,but i'd vote for "A".For "B",yes,of course,light doesn't necessarily come from the sun,but MOST OF IT DOES...
    As for "C",u'd have to read Richard P.Feynman's book "QED:A Strange Theory of Light and Matter"...But in the simple context of classical physics,"A" is rhe correct answer.

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