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!

Linear density

  1. Nov 13, 2004 #1
    I had a problem with finding the moment of inertia. I have a rod and it has linear density[tex]\lambda=4.0kg[/tex] and the equation for its moment of inertia is [tex]I=\frac{1}{12} ML^2[/tex] now I have an axis at the center of mass of a rod the rod has a total length [tex]L=4m[/tex] so in my equation I would have to substute [tex]\lambda L=M[/tex] now the thing that I dont understand is if my center of mass horizontal cordinate is [tex]2m[/tex] the length I multipy by lambda should be 2m correct?
     
  2. jcsd
  3. Nov 14, 2004 #2
    Kg is not the unit for linear density. I'm assuming you meant [itex]4.0\frac{kg}{m}[/itex]. If each meter of the rod has a mass of 4.0kg, why would you only multiply by half the length of the rod to get its mass? I think [itex]M=(4.0\frac{kg}{m})(4.0m)[/itex]. Does that give you the right answer?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook