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Homework Help: Combining formulars

  1. Dec 17, 2009 #1
    Hi guys

    I have question in my homework to rearrange 2 equations. see picture attached.

    the equation has to have F as the subject and not have Ev in the equation.

    Can someone point me in the right direction please


    Attached Files:

  2. jcsd
  3. Dec 17, 2009 #2
    I´ll help you with the first step:
    Both formulars express Eph.
    So you have to replace Eph in both of them and write the remaining parts as one equation.
    Then the rest should be easy.
    Last edited: Dec 17, 2009
  4. Dec 17, 2009 #3
    Ah right.

    Thanks for the help by the way.

    I have attached my first atempt. Is this correct or could you tell me where I have gone wrong?


    Attached Files:

  5. Dec 17, 2009 #4
    Maybe what I'm saying is stupid, but can't you simply put them together?
    By doing so, you would have:

    hc*t/b= h*f
    then you can transform it into

    f= hc*t / (b*h)

    EDIT: pardon me...I haven't seen that someone had already answered...
  6. Dec 17, 2009 #5
    Seems perfectly correct to me.
  7. Dec 17, 2009 #6

    Thanks for the help guys.

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