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Homework Help: Object Beneath the Water Problem

  1. Mar 11, 2012 #1
    1. The problem statement, all variables and given/known data
    A small logo is embedded in a thick block of transparent material (n = 1.81), 4.03 cm beneath the top surface of the block. The block is put under water (n = 1.333), so there is 2.15 cm of water above the top surface of the block. The logo is viewed from directly above by an observer in air. How far beneath the top surface of the water does the logo appear to be?

    2. Relevant equations
    apparent depth = d ((n_2)/(n_1))

    3. The attempt at a solution
    First was 4.03(1.33/215) it was wrong.
  2. jcsd
  3. Mar 11, 2012 #2
    For the block in water I used n2/n1 = real/apparent depth.
    n2 is the block, n1 is the water. I got 2.96cm as the point in the block from which the light appears to come from into the water.
    You can now take this point to be at a depth of 2.15 + 2.96 in WATER
    then do n2/n1 = real/ apparent again ( I got 4.58cm from water surface)
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