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Charged Particles (Potential Energy)

  1. Sep 28, 2015 #1
    1. The problem statement, all variables and given/known data
    Figure 24-21 shows four pairs of charged particles with identical separations. (a) Rank the pairs according to their electric potential energy (that is, the energy of the two-particle system), greatest (most positive) first. (b) For each pair, if the separation between the particles is increased,does the potential energy of the pair increase or decrease?
    image102120141236.png
    2. Relevant equations
    U = W = (kq1q2)/r
    3. The attempt at a solution
    For part a, I got the ranking 3,2,4,1 by subtracting the second particle from the first one. ie. (1) -2-(+6) = -8
    For part b, I got 1,4 increase whereas 2,3 decrease from the equation.
    I haven't gotten the answers to these but I want to make sure I'm right.
    Thank you! :oldbiggrin:
     
  2. jcsd
  3. Sep 28, 2015 #2

    SammyS

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    Not correct.

    Did you use the relevant equation ?
     
  4. Sep 28, 2015 #3
    Would this be right?
    a. 3=4>2=1
    b. 3&4 decrease 1&2 increase
     
  5. Sep 28, 2015 #4

    SammyS

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    That looks to be correct .
     
  6. Sep 28, 2015 #5
    Thank you!
     
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