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

Homework Help: Mirrors radius of curvature

  1. Oct 28, 2005 #1


    Some rearvier mirrors produce images of cars behind you that are smaller than they would be if the mirror were flat. Are the mirrors concave or convex? What is the mirror's radius of curvature if cars 20.0 m away appear 0.33x their normal size.

    My Answers

    The mirrors are concave.


    f=3.3 m

    Is this correct?

    Thank you:smile:
  2. jcsd
  3. Oct 28, 2005 #2

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    the mirrors are NOT concave. What's your next guess?:tongue2:

    ANd no, your math is not correct.
    Use the magnification equation to find the image distance.
    Use the "thin lens" equation (it's the same for mirrors) to find the focal length.
    then proceed.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook