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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


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  4. Mar 30, 2008 #3
    Ok thanks, so i must've made a mistake somewhere...
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