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Homework Help: Potential Multiple Choice

  1. Oct 27, 2011 #1
    1. The problem statement, all variables and given/known data
    Charge Q is located at the (x,y) origin. q is a distance r in the +x direction from Q. 2q is a distance 2r in the +x direction from Q. Which of q or 2q is at a higher potential? q, 2q, or same.

    3. The attempt at a solution
    I am thinking that it would depend on Q. Q=0, then the higher potential is at q. But if it wasn't =0? The fact that 2q and q impact each other's potential also makes this problem difficult. Any thoughts?
  2. jcsd
  3. Oct 27, 2011 #2
    We know that [tex]V=\frac{kq}{R}[/tex], correct? Do all potential calculations at the origin. For example, measure the potential due to q, and 2q at the origin where Q is located.

    What do you get?
  4. Oct 27, 2011 #3
    Wouldn't it be the same for 2q and q? But if you mean add them together than V = kq(squared) / r. No?
  5. Oct 27, 2011 #4
    Does the question indicate whether Q is positive or negative?
  6. Oct 27, 2011 #5
    No, it does not.
  7. Oct 27, 2011 #6
    The sign of Q is the determining factor in this situation.
  8. Oct 28, 2011 #7
    Then what would be the answer for both cases?
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