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Homework Help: Potential energy of the system increase or decrease?

  1. Oct 8, 2005 #1
    When two electrons move away from each other, does the potential energy of the system increase or decrease?
     
  2. jcsd
  3. Oct 8, 2005 #2

    Physics Monkey

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    What work have you done? What is the potential energy of two electrons separated by a certain distance?
     
  4. Oct 8, 2005 #3
    No, this is a question where numerial values are given. I thought that the totla potential energy stays the same because they both move off in differnt directions
     
  5. Oct 8, 2005 #4

    Physics Monkey

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    I don't understand, what are you saying "no" to?

    Why do you think this? Again let me ask, what is the potential energy of two electrons separated by a certain distance? How does it change with the distance?
     
  6. Oct 9, 2005 #5
    In this case the potential energy of the system is given by k(-e)(-e)/r where r is the distance between the axes. As the two electrons move away from each other , the 'r' increases and thus the P.E decreases , because the system will always prefer to have minimum PE , therefore two electrons SHOULD remain away from each other.That is why the two electrons repel each other.

    BJ
     
  7. Oct 9, 2005 #6

    Tide

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    HINT: If the sum of the kinetic and potential energy is a constant and the kinetic energy increases what happens to the potential energy?
     
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