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Homework Help: Total energy in a circuit

  1. Sep 17, 2008 #1
    1. The problem statement, all variables and given/known data
    for this problem i found all of the separate capacitence for each capacitor, each potential difference, and each charge on each capacitor but im not sure how to get the total energy stored for the whole system. does anybody know the correct equation

    2. Relevant equations


    3. The attempt at a solution

    i tried using the total capacitance of the system and the total voltage.. to no avail
  2. jcsd
  3. Sep 17, 2008 #2


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    Hi goWlfpack! :smile:

    Energy in capacitor = (1/2)CV2 :smile:
  4. Sep 17, 2008 #3


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    The equation for energy in a capacitor should be in any physics textbook that talks about capacitors. Try looking carefully through that section in your book.
  5. Sep 17, 2008 #4
    ok so i used the equation total energy = (1/2)CV^2

    but it says i am off by a multiple of ten.

    can anybody help me with the conversion.
    the capacitance is in micro farads
    the potential difference is in volts
    and they want the answer in looks like milli joules
  6. Sep 17, 2008 #5


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    Did it say a multiple of ten or a power of ten?

    I would convert your numbers to Farads and Volts, plug those into the equation to get an energy in Joules, then convert that to mJ.
  7. Sep 17, 2008 #6
    thanks guys! got it! thats exactly what i did. converted everything to the standard. Thanks so much!
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