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Distance an electron traveled

  1. Nov 6, 2012 #1
    1. The problem statement, all variables and given/known data
    A very long, thin straight line of charge has a constant charge density of 2.0 pC/cm. An electron is initially 1.0 cm from the line and moving away ( that is, perpendicular to the line ) with a speed of 1000 km/s. How far does the electron go before it comes back?


    i cant seem to find the required equations in my textbook. any help would be great.
     
  2. jcsd
  3. Nov 6, 2012 #2

    tiny-tim

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    Hi Zarrey! :smile:
    Use conservation of energy. :wink:

    (same for your other thread)
     
  4. Nov 6, 2012 #3
    wow lol. i cant believe i didnt know that. thank you for reminding me :D
     
  5. Nov 6, 2012 #4
    Conservation of energy is different when dealing with electrons it seems. is mass relevent?
     
  6. Nov 6, 2012 #5
    First, you need to find the field around the line of charge as a function of distance. Gauss' theorem wil do nicely do to the symmetry.
    Then you can use the work-energy theorem.
     
  7. Nov 7, 2012 #6

    tiny-tim

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    no
    mass always comes into the KE formula

    mass is also relevant if it comes into the PE formula
     
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