Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Stokes Law, Viscosity. (very simple)

  1. Mar 30, 2008 #1
    I'm trying to find the viscosity of some glycerol that we dropped various steel balls down using the equation:

    V = [2r^2 (p – σ) g] / 9η

    I put in these values:
    p = 7800 kg m-3
    σ = 1200 kg m-3
    g = 9.8 m s-2

    And ended up with the equation. η = 129360r^2 / 9V

    My problem is that I thought viscosity is a constant. When I put my values in the viscosity decreases as radius decreases.
  2. jcsd
  3. Mar 30, 2008 #2


    User Avatar

    Staff: Mentor

  4. Mar 30, 2008 #3
    Ok thanks, so i must've made a mistake somewhere...
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?