1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

A little question

  1. Jul 4, 2009 #1

    if i have lets say a rod swinging on a pivot, and i calculate the moment of inertia around the axis, which is the pivot, and i get the angular acceleration.
    now lets say i want to the the same around the other end of the rod, but the thing is that in the lab F.O.R it is moving around the pivot, although in the F.O.R of the other end of the rod, the pivot moves around that end, so why can't i make the same equations, and substitute angular acceleration with the one that i got before, and then find the net torque,
    i mean, because it's an accelerated f.O.R i need to be careful, and add some factious forces and stuff, so how do i deal with that?
  2. jcsd
  3. Jul 4, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    Hi Dweirdo! :wink:

    Yes, you can do that … see, for example, http://en.wikipedia.org/wiki/Fictitious_force :smile:
  4. Jul 4, 2009 #3
    Hi Tim,and thanks
    I've looked it p, but which one of these should i use in my case:
    1)Rotating observer
    2)Rotating coordinate systems

    and what is this symbol:Ω?
    thanks :)
  5. Jul 4, 2009 #4


    User Avatar
    Science Advisor
    Homework Helper

    Theyr'e the same aren't they? :confused:

    (and Ω is angular velocity)
  6. Jul 4, 2009 #5
    idk they come up as 2 different sectors :P oh well
    and why the hell they have to make things so complicated , omega should be angular velocitY!!!!!!!! :P
    thanks again,
  7. Jul 4, 2009 #6
    never mind, silly question :(
  8. Jul 5, 2009 #7
    Frame of reference-F.O.R :P
  9. Jul 5, 2009 #8


    User Avatar
    Science Advisor
    Homework Helper


    Hi Dweirdo! :smile:

    Ω is capital ω … see http://en.wikipedia.org/wiki/Greek_alphabet :wink:

    (that's partly why someone with a sense of humour made Ω the symbol for ohm! :biggrin:)
  10. Jul 5, 2009 #9
    haha cool :) still omega sounds way smoother :P
    i still think they just try to make things complicated :)
    *goes to study greek alphabet* :DD
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook