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!

Viscosity,Fluid flow and terimal velocity

  1. Dec 1, 2011 #1
    1. The problem statement, all variables and given/known data
    When does Fb(Buoyancy force) equal the drag force(FD)?
    and Fb+FD=Fg

    2. Relevant equations
    Fb=density of water times volume of water times 9.80 m/s^2
    FD=6pi times viscosity times radius times v
    Fg=mg
    3. The attempt at a solution
    All ik is the solid has 2 be in the air going to the water but idk how 2 really prove that please help me
     
  2. jcsd
  3. Dec 2, 2011 #2
    This problem is really confusing. Do we have a ball falling in water? Not sure what is going on here.
     
  4. Dec 2, 2011 #3

    ehild

    User Avatar
    Homework Helper
    Gold Member

    It is a sphere of radius r moving with speed v in a fluid of viscosity η. The drag force is FD=6πηrv.
    The buoyant force is FB=ρVg, where ρ is the density of the liquid and V is the volume of the sphere.

    ehild

    PS: ChunkymonkeyI, what did you mean: "All ik is the solid has 2 be in the air going to the water but idk how 2 really prove that please help me" We use English here.
     
    Last edited: Dec 2, 2011
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Viscosity,Fluid flow and terimal velocity
  1. Fluids (Viscosity) (Replies: 3)

Loading...