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Homework Help: Cannot see where potential enegy comes from in classical mechanics

  1. Jun 30, 2009 #1
    1. The problem statement, all variables and given/known data

    F=force, a=acceration, m=mass, U potential energy, P momentum, E=energy

    How do derive 2 and 3 from 1( see below).

    2. Relevant equations

    1) F=ma,

    2) E= (p^2)/(2m) + U,

    3) ma = -del U

    3. The attempt at a solution

    I try to understand why U pop into the equation for 2 and 3 given only 1, but i failed. I do not know how to introduce the notion of potential energy given only 1.
  2. jcsd
  3. Jun 30, 2009 #2


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    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi vectorcube! Welcome to PF! :smile:

    U is the potential, not the potential energy …

    see the PF Library for more details. :wink:
  4. Jun 30, 2009 #3


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    Gold Member

    Oops scratch my post, wrong derivation
    Last edited: Jul 1, 2009
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