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Homework Help: Light - Lens Help

  1. Mar 4, 2004 #1
    I have two questions that i couldn't do, it aint that hard:

    1.An object is placed 30.0cm from a convex lens of f=10.0cm. Find the position and the magnification of an image. (f = focal length)

    An object is placed 20.0cm from a convex lens of f=30.0cm. Find the position and the magnifying factor of an image.
  2. jcsd
  3. Mar 4, 2004 #2
    You can draw ray diagrams to help you, or use the lens formula (1/u + 1/v = 1/f) if you've learnt it.
  4. Mar 4, 2004 #3


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    Science Advisor

    You also posted this in the "General Physics" section where I responded. Please do not multi-post!
  5. Mar 4, 2004 #4
    I attached the file with the answers....

    This really isn't a problem that should require help... nor be in the college level help section. I am currenty in my junior year of high school and we are currently doing 4 and 5 mirror and lens combo problems.http://www.quantumninja.com/random/lens.jpg

    The actual calculations are based upon 1/o+1/i=1/f
    and Mag=-i/o

    The final answers I belive came out to be I=15 cms M=1/2 x for problem one and I=-60 cm M=3x for problem 2
    Last edited: Mar 4, 2004
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