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Homework Help: Refractive index, light ray help

  1. Oct 21, 2007 #1
    Hi, this is the question in my homework.

    Explain what happens when a light ray enters and leaves a glass block if it hits the face of the block at right angles to it.

    Can someone pelase help me, i think that the light ray would just go straight through the block without bending but im unsure and it requires a more in depth answer than that so if anyone can, its greatly appreciated.

  2. jcsd
  3. Oct 21, 2007 #2

    Doc Al

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    Staff: Mentor

    Refraction is governed by Snell's law. Look it up and see what it says about this situation.
  4. Oct 22, 2007 #3


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    Homework Helper

    Refractive index, light ray help Reply to Thread

    Yes. The light will travel through the glass block without bending. But its path inside the block gets shortened.
    Apparent path = real path /refractive index
    If you see the source of light from the other side of the block , you feel that the source of light is nearer.
  5. Oct 22, 2007 #4

    Doc Al

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    Staff: Mentor

    That's true when viewing a light source (and is also explained by Snell's law), but this question only refers to a single ray that makes a right angle to the surface. A light source will have many rays at all angles.

    To answer this question, apply Snell's law.
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