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!

Inertial forces, relative strength, basic q.

  1. Jan 15, 2014 #1
    The question is to rank the inertial forces, euler,coriolis and centrifugal in increasing order of strength, for a observer in the Earth' rotating frame, observing a body stationary in the UK.

    My thoughts are that coriolis = 2mw X (dr/dt), and so depends on the velocity so can only come into play when there is motion.

    A similar argument would hold for the euler force: m(dw/dt) X (dr/dt) . (Even without the dr/dt =0, my book says that dw/dt approximates zero, so this force would be zero anyway.

    This would give the order : centrigufal, corilios/euler - with coriolis and euler tied.

    However I'm not 100% sure dr/dt =0 - does this correspond to only translational motion?

    (The question does not mention any of the forces being of equal strength, so I assume I am wrong somewhere...)

    Thanks for your help guys !
     
  2. jcsd
  3. Jan 15, 2014 #2

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    That's wrong (it's even dimensionally wrong). Try m(dw/dt) X r.
    To answer completely, you'd have to investigate whether the Earth's angular rotation ever changes. If the Coriolis force is definitely zero here (I agree) then any nonzero Euler force will break the tie.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted