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

Light, Mirrors, Lenses, immediate help required!

  1. May 31, 2005 #1
    Hello, here is the problem i am having trouble with. The sun falls on a concave mirror and forms an image 3 cm from the mirror. If an object 24mm high is placed 12 cm from the mirror, where will its image be formed? So far, i have decided that since 1/f = 1/do + 1/di...
    1/f = 1/do + 1/3 = 1/12 + 1/di
    I also decided that hi/2.4 = -di/12... The problem is...even if i solve for di in terms of hi and plug that into my first equation i dont have enough information to solve for do. Im stuck and this problem is due tomorrow... please help
  2. jcsd
  3. May 31, 2005 #2


    User Avatar
    Science Advisor
    Homework Helper

    You need to use the "sun" information to find the focal length of the mirror. The sun is an object at distance ___________ that forms an image at 3cm. What is f?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook