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Work done and P.E

  1. Dec 8, 2003 #1
    Dear all

    I know that E(grav) = -GmM / r, Can I use Work done = F x s to calculate the P.E between two mass of the space? Thank a lot.Good Bye

  2. jcsd
  3. Dec 8, 2003 #2
    No, I don't think so because F isn't a constant in a G-field, but we can use integration to derive the formula, E(grav) = -GmM / r.

    dw = - F dx

    [tex]\int ^{w'}_{0} dw = - \int ^{\infty}_{r} \frac{GMm}{x^2} dx[/tex]

    [tex]w' = -\frac{GMm}{r} [/tex]

    Where w' is the work required to take an object from infinity to a particular point in a G-field, with distant r away from the other object.
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