1. Limited time only! Sign up for a free 30min personal 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!

Simple problem i need help with

  1. Sep 2, 2008 #1
    im new to the physics world and know this is probably an easy problem but i dont know where to start

    Hold a pencil in front of your eye at a position where its end just blocks out the moon. Make approprite measurements to estimate the diameter of the moon, given that the earth-moon distance is 3.8x10^5km.

    i figured that you prob had to measure the end of a pencil which i measured about 1.5 cm which is 1.5x10^-5km but i dont really know what to do from there.
  2. jcsd
  3. Sep 2, 2008 #2


    User Avatar
    Homework Helper

    How far away was the pencil from your eye?
  4. Sep 2, 2008 #3
    about 15cm
  5. Sep 2, 2008 #4
    so use simular triangle theory?
  6. Sep 3, 2008 #5


    User Avatar
    Homework Helper

    Yes, that would do it nicely.

    Sorry for late reply I guess I missed it last night when I scanned the board.

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

Similar Discussions: Simple problem i need help with