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Homework Help: Annoying electrostatic question

  1. May 10, 2010 #1
    so today we had a test about electrostatics.
    here was the question:

    a positive charged rod (ungrounded) is to the left of 2 metal conducting spheres, that are initially touching each other. Each metal conducting sphere is hung by a string (which is an insulator). What is the charge of each sphere when the spheres are seperated, and the positive charged rod remains where it is?

  2. jcsd
  3. May 10, 2010 #2
    It depends on the exact positions of the spheres. The rod will pull more electrons on the sphere that is closer.
  4. May 10, 2010 #3
    let me rephrase the question: when the spheres seperate, is one of them positive, and another negative, or do they both become neutral?

    please explain. thanks
  5. May 10, 2010 #4
    If I understand your question correctly, the sphere closer to the rod would be negatively charged while the other one would become positively charged. When the spheres were touching the electrons would build up on the sphere closer to the rod because of opposite charges while the other one would become positively charged due to a loss negative charges.
  6. May 10, 2010 #5
    absolutely correct. my question is, what happens when the 2 spheres are seperated? does one become positively charged, and the other become negaitvely charged?
  7. May 10, 2010 #6
    Well if there is nothing touching the two spheres together then they will remain with their respective charges.
  8. May 10, 2010 #7
    do u mean their both neutral?
  9. May 10, 2010 #8
    No I mean the one will be positive and the other will be negative.
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