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Homework Help: Mixing two liquids with equal mass, find pressure

  1. May 17, 2010 #1
    1. The problem statement, all variables and given/known data
    A mass of a liquid of density ρ is thoroughly mixed with an equal mass of another liquid of density 2ρ. No change of the total volume occurs.


    2. Relevant equations



    3. The attempt at a solution
    i tried to use ρ=[tex]\frac{m}{v}[/tex]
    then v=[tex]\frac{m}{\rho}[/tex]
    therefore v1+v2=V
    [tex]\frac{m}{\rho}[/tex]+[tex]\frac{m}{2\rho}[/tex]=v
    [tex]\frac{3m}{2\rho}[/tex]=V
    [tex]\frac{3m}{2V}[/tex]=[tex]\rho1[/tex]
    [tex]\rho1[/tex] \ [tex]\rho[/tex]
    in the end i get [tex]\rho1[/tex] = [tex]\frac{3}{2}[/tex][tex]\rho[/tex]

    but i was wrong couldnt find out the reason ><
     
  2. jcsd
  3. May 17, 2010 #2

    rl.bhat

    User Avatar
    Homework Helper

    Re: Pressure

    Total volume V = 3m/2ρ

    Total mass = 2m

    So new density ρ' = 2m/V = ....?
     
  4. May 17, 2010 #3
    Re: Pressure

    oh no
    !@#$%^&*()
    =.=
    cant think that this could be that simple ><
    but anyway its the right answer
    ths for solving it for me
     
    Last edited: May 17, 2010
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