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!

Homework Help: Rotatinal inertia help?

  1. Aug 2, 2010 #1
    1. The problem statement, all variables and given/known data
    How do I find Rotational inertia of this?http://yfrog.com/e4asdfasdfasdfj. Assumed thin rod (ignore r).

    2. Relevant equations
    I=1/12 M L2

    3. The attempt at a solution
    Cause that equation applies if the rotation axis is at the center, so I doubled d (and got like (2d)2 and (4d)2) and used the equation, but I ended up with something like 5/3Md2, but the answer at the back says its 8/3Md2.
  2. jcsd
  3. Aug 2, 2010 #2

    Doc Al

    User Avatar

    Staff: Mentor

    If you know the rotational inertia about the center of mass, use the parallel axis theorem to find the rotational inertia about the end.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook