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Homework Help: Determining Focal Length

  1. Apr 28, 2009 #1
    1. The problem statement, all variables and given/known data
    Without her contact lenses, Kat cannot clearly see an object more than 70.0cm away. What should be the focal length of her corrective contact lenses?

    2. Relevant equations
    1/f = 1/p + 1/q

    3. The attempt at a solution
    1/f = 1/infinity + 1/-70.0cm = -0.0143cm
    f = -70.0 cm

    Would anyone be able to please check this answer? Thank you!
    Last edited: Apr 28, 2009
  2. jcsd
  3. Apr 28, 2009 #2


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    Homework Helper

    Your answer is correct.
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