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Charging/discharging capacitor

  1. Jun 21, 2009 #1
    1. The problem statement, all variables and given/known data
    Questions 1-2:
    Switch is ON and left for a very long time.
    1) current in circuit after this time
    2) energy in capacitor after this time

    Questions 3-4:
    Capacitor then hooked up to resistor.
    3)Energy after another long time.
    4)What happens to the energy that was in the capacitor before it was hooked up to the resistor.

    2. Relevant equations
    U = 1/2 CV^2

    3. The attempt at a solution
    1) current is 0 because after the capacitor is fully charged no current flows
    2)just solve using U=1/2CV^2
    3)Energy = 0 because capacitor would be discharged
    4)energy goes into heat

    I'm not sure about all these answers... can someone let me know if my thought process is correct? Thanks for any help!
    Last edited: Jun 21, 2009
  2. jcsd
  3. Jun 21, 2009 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    Looks okay to me.
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