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Homework Help: Fraction question

  1. Nov 14, 2006 #1

    I'm terrible with fractions and would appreciate any help regarding this problem.

    This is a problem from my physics course.

    F2 = [ (v + v2)/(v + v1) ] F1

    I need to solve for v1. I am given the values for F2, v, v2, and F1 and need to turn the formula around to solve for v1..

    F1 = 400
    F2 = 420
    v = 344
    v2 = 26.82

    My attempt was F2/(F1(v+v2)) = 1 / (v+v1)

    but this is wrong..

    any suggestions?
  2. jcsd
  3. Nov 14, 2006 #2
    [tex] F_{2} = \left \frac{v+v_{2}}{v+v_{1}}\right F_{1} [/tex]

    So [tex] F_{2}(v+v_{1}) = F_{1}(v+v_{2}) [/tex]

    [tex] v + v_{1} = \frac{F_{1}(v+v_{2})}{F_{2}} [/tex]

    [tex] v_{1} = \frac{F_{1}(v+v_{2})}{F_{2}} - v [/tex]
    Last edited: Nov 14, 2006
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