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Homework Help: Equation derivation problem

  1. Sep 10, 2010 #1
    Hey
    this is a pretty straight forward equation derivation, but when i do it and compare it to the solutions, mine is different to theirs.
    The equation is
    [PLAIN]http://img213.imageshack.us/img213/9790/ddaaad.jpg [Broken] where n1=1
    for a concave lens (fish in a fish bowl) so r is negative

    solving for i

    they get, r/(n2+1)

    and i get n2r/(n2+1)

    there answer seems right for the question, but im just not sure how they canceled the n2
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 10, 2010 #2

    rl.bhat

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    Post the actual problem in the book.
     
  4. Sep 10, 2010 #3
    [PLAIN]http://img228.imageshack.us/img228/593/dsdsdsaas.jpg [Broken]

    p = r/2 n2 = water
     
    Last edited by a moderator: May 4, 2017
  5. Sep 10, 2010 #4

    rl.bhat

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    The fish is inside the bowl. So the formula becomes

    n1/p + n2/i = (n1 - n2)/r

    Here n1 = 1.33 and n2 = 1.

    Now simplify and find i.
     
  6. Sep 10, 2010 #5
    oh right
    thanks alot
     
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