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Homework Help: Point charges acceleration

  1. Sep 12, 2010 #1
    Q1. If two point charges have equal mass and and charg are released on a frictionless table, each has an initial acceleration (Ao). if instead you keep one fixed and release the other one, what will be its initial acceleration?Ao,2Ao or Ao/2?


    Q2. A point charge of mass (m) and charge (q) and another point charge of mass (m) but charge (2q) are released on a frictionless table. If the charge (q) has an initial acceleration (Ao), what will be the acceleration of (2q)?Ao, 2Ao, 4Ao,Ao/2, or Ao/4?
     
  2. jcsd
  3. Sep 12, 2010 #2

    diazona

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    Show us what you've tried and what you know that might be relevant to the problem.
     
  4. Sep 12, 2010 #3
    Q1 Since both charges are the same they will repel one another. So I was comparing this problem to a ping pong ball problem I had in Physics I, when the force of the wall equals the force of the ball thrown. Wouldn't the acceleration just be Ao?

    Q2 Since F=ma the mass is proportional to the acceleration therefore the acceleration should be 2Ao.
     
  5. Sep 12, 2010 #4

    diazona

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    1. I believe you're correct

    2. Look at that equation carefully: the mass is not proportional to the acceleration.
     
  6. Sep 13, 2010 #5
    They are inversely proportional so the acceleration should be Ao/2?
     
  7. Sep 13, 2010 #6

    diazona

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    You're right that in F=ma, the mass and acceleration are inversely proportional. But what are the masses of the two particles?
     
  8. Oct 10, 2012 #7
    i think you are wrong guys, cuz it's an electric force not an applied force.
    so the acceleration = Ao . o:)
     
  9. Oct 10, 2012 #8
    i think you are wrong guys, cuz it's an electric force not an applied force.
    so the acceleration = Ao .
    [they have the same acceleration ]
     
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