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Homework Help: Work-Kinetic Energy question

  1. Sep 18, 2011 #1
    This question is whooping me. I know I have the calculus part right I just dont know where to go from here?

    A particle moving along the x axis is acted upon by a single force F = F0e^(–kx), where F0 and k are constants. The particle is released from rest at x = 0. It will attain a maximum kinetic energy of


    So using the Work Kinetic Energy theorem
    W=Kf-Ki since x=0 then Kf=W

    W=integral(F = F0e^(–kx),x,0,xf)
    taking F0 out, since its a constant, and integrating the exponential function I get
    W=F0[-e^(-kxf)/k + 1/k]

    now what????
  2. jcsd
  3. Sep 18, 2011 #2
    When you evaluate the integral one of the terms is zero,

    exp(-x) goes to zero as x goes to infinity?
  4. Sep 20, 2011 #3
    I did that, that's why the second term inside the brackets is 1/k, since e^(-k*0)=1.
  5. Sep 20, 2011 #4


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    Homework Helper

    You've pretty much done it now. So you now have 1/k inside the bracket and f0 outside the bracket, so just multiply them together to get the answer.
  6. Sep 24, 2011 #5
    Ok, that makes sense. I was there I just couldn't see it. Thanks all.
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