1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Optics, calculating image distance,.given magnification and focal length

  1. Jan 3, 2013 #1
    1. The problem statement, all variables and given/known data
    The image obtained with a converging lens is upright and 3x the length of the object. The focal length of the lens is 20cm. Calculate the object and image distances


    2. Relevant equations

    I have absolutely no idea how to even start this question

    3. The attempt at a solution
    1/object + 1/image = 1/focal (lens equation )
    1/ob + 1/im= 1/20

    M = ob/im ( magnification formula)
    3= ob/im

    I tried solving for each variable but it wasnt working...
     
  2. jcsd
  3. Jan 3, 2013 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member

    Hi Faria, welcome to PF.

    The magnification formula is wrong, look it after. And then show your work in detail.

    Is the image real or virtual if the image is upright?

    ehild
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook