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Homework Help: Ordinary differential equation question

  1. Jan 24, 2008 #1
    1. The problem statement, all variables and given/known data

    What is the general solution to the following ODE

    F=X''m where F and m are both constants

    2. Relevant equations

    3. The attempt at a solution

    I got X=(k/2)t^2 + C

    I got this from F/M being just another constant K, and X'' being (d^2 X)/(dt^2) so you just integrate k twice with respect to t, the first giving kt, and the second giving (k/2)t^2 + C. Is this correct?
  2. jcsd
  3. Jan 24, 2008 #2
    almost but not quite,

    assuming m != 0, F = X''m => F/m = X'' , so X' = (F/m)x + C, say k = F/m, so

    X' = kx + C, now integrate again,

    X = kx^2/2 + Cx + D
  4. Jan 24, 2008 #3
    yep, stupid mistake. thanks alot!!
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