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Homework Help: Confusing Force function

  1. May 13, 2010 #1
    1. The problem statement, all variables and given/known data
    The force on a particle is directed along an x axis and given by [tex] F = F_0(\frac {x}{x_0} -1) [/tex]. Find the work done by the force in moving the particle from x = 0 to [tex] x = 2x_0 [/tex]

    2. Relevant equations
    F=ma, W=Fd, etc.

    3. The attempt at a solution
    I don't even know how to interpret that function. Does the [tex] x_0 [/tex] mean the initial position? Does [tex] F_0 [/tex] mean the initial force? I'm so confused. Any help would be appreciated.
  2. jcsd
  3. May 13, 2010 #2


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    Hi DrummingAtom! :smile:

    (try using the X2 tag just above the Reply box :wink:)
    That's right :smile:

    a "0" subscript always means a constant (usually the value at t = 0). :wink:

    (oh … except in relativity, where x0 means time! :rolleyes: :biggrin:)
  4. May 13, 2010 #3
    I'm still confused on this one. So, if x0 F0 are constants then how would the graph of this function look? Because they want you to graph F(x) before integrating. I mean what do you pick for your constant in a situation like this? I know it's going to be a linear function.
    Last edited: May 13, 2010
  5. May 13, 2010 #4


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    It doesn't really matter, as long as x0 is not 0 (otherwise you'll have a divide by zero problem). But if you want to make your life easier, put it on the positive x-axis somewhere. I suggest putting it at x = 1. That way you'll integrate from 0 to 2. But don't label you x-axis with '1' and '2'; rather label you x-axis to go from


    Now when you consider your graph's labels, you are integrating from 0 to 2x0, as the problem specifies! :cool:

    The y-axis is F. So where does F0 fit into your graph? I'll let you do that.
    Last edited: May 13, 2010
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