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: Moment of inertia for a cylinder at a distance from rotation axis

  1. Jun 26, 2007 #1
    1. The problem statement, all variables and given/known data
    I have a cylinder, for which i want to find the inertia tensor.
    Where the rotational axis are either the x (red) or y (green).

    2. Relevant equations
    I know that the inertia tensor for a cylinder is of the form
    Then I believe that the bottom right element stays the same, since this describes the rotation around the z-axis.
    The tricky part for me is the rest of the matrix. I am no expert, and do not understand inertia tensors fully, so I would like some pointers.

    3. The attempt at a solution
    My immediate idea is that the matrix should remain in its diagonal form, the zeros will remain zeros, is this correct?

    I know that for complex forms i can split up the moments of inertia, so i have the moment of inertia for the blank space d, which is 0. and then i can add the moment of inertia of the cylinder, but how do i calculate this, when the rotational axis is x-axis for example?
  2. jcsd
  3. Jun 26, 2007 #2
    I had a sudden struck of enlightment...
    Is it really as simple as just taking d+h and and using as h in the matrix?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook