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!

Moment of Inertia for Simple Polygon

  1. Jul 8, 2016 #1
    I am trying to determine if a function I have is working correctly. The function computes the moment of inertia for a polygon. To test the function I created a polygon that has 4 points and represents a square of 4 units by 4 units. The answer I am getting is 32. I believe the answer should be 42.6 based on J0= Ixx +Iyy, where Ixx = (bh^3)/12 and Iyy = (hb^3)/12.

    The function I have is implementing the following.

    Which is correct 32 or 42.6?
  2. jcsd
  3. Jul 8, 2016 #2


    User Avatar

    The correct polar moment of inertia for a square: J = a^4/6 where a= length of the sides
    In your case: J = 4^4/6 = 42.666...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted