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 tensor about y-axis of a cylinder.

  1. May 12, 2013 #1
    1. The problem statement, all variables and given/known data

    What must the ratio of height to radius of a cylinder be so that every axis
    is a principal axis (with the CM as the origin)?

    2. Relevant equations

    Moment of inertia tensor.
    I need I_yy = [itex]\sum m *(x^2 + z^2)[/itex]

    3. The attempt at a solution

    I calculated I_zz = MR^2 /12 . Now I change the principal axis to y-axis. I need to determine the moment of inertia tensor of it. Polar coordinates won't work. If I go for cartesian, I do not know the limits for the dx.
     

    Attached Files:

  2. jcsd
  3. May 12, 2013 #2

    TSny

    User Avatar
    Homework Helper
    Gold Member

    You can perform the integral using cylindrical coordinates ##\vec{r} = (r\cos\theta, r\sin\theta, z)##.
     
  4. May 13, 2013 #3

    TSny

    User Avatar
    Homework Helper
    Gold Member

    Also, the result for ##I_{zz}## is not correct. You should get a different factor than 12 in the denominator.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Moment of inertia tensor about y-axis of a cylinder.
Loading...