Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Optics of lenses and mirrors question:

  1. Dec 15, 2011 #1
    So I was going through the playlist of videos here, and have understood everything so far. However, they are going through this question and he introduces this chart, so the student can use it as a reference to know if he got the answer correct.



    What I did not understand is, how did he know 24cm lines up with F (within the focal point) as opposed to 2F?

    Have I missed a key piece of information?
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?