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Homework Help: Coloumbs Law Problem

  1. Aug 26, 2008 #1
    1. The problem statement, all variables and given/known data

    Two equally charged particles are held 3.2x10^-3 m apart and then released from rest. The initial acceleration of the first particles is observed to be 7.0m/s^2 and that of the second to be 9.0 m/s^2. If the mass of the first particle is 6.3x10^-7 kg , what are a.) the mass of the second particle, and b) the magnitude of the charge on each particle.

    2. Relevant equations

    Coloumbs Equation

    3. The attempt at a solution

    kinda need some help how to start this problem.
  2. jcsd
  3. Aug 26, 2008 #2


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    Use Newton's second law here to get the force associated with the 1st particle. Note that the force exerted by the 1st on the 2nd is the same as the one by the 2nd on the first. From here you can find a). Hm is that all you're given? Because I don't see how you can find the individual charges. Both particles are released at the same time?

    EDIT: Sheesh, should have read it more closely. The question states that both charges have the same magnitude. In that case, just use Coulomb's law to find it.
  4. Aug 26, 2008 #3


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    OK what are the variables in Coulomb's Equation?
  5. Aug 26, 2008 #4
    What does Coloumb's law say about the force on the two particles? What does Newton's laws say about the force on the two particles? Will the forces bring them together or push them apart? Start with this. If you can't get it, make a post showing what you tried using these laws and someone will probably provide more information.
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