Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calculating expended energy in a battery

  1. Mar 30, 2010 #1
    1. The problem statement, all variables and given/known data
    How much energy must a 42 V battery expend to fully charge a 3.62x10-6 F and a 6.11x10-6 F capacitor when they are placed in parallel?


    2. Relevant equations

    capacitor in parallel therefore total capacitance is the sum...

    3. The attempt at a solution
    I thought that you could use U=Vq but apparently you can't because I was getting the wrong answers.. this is the same question that I tried to do before but with different values. HELP :)
     
  2. jcsd
  3. Mar 30, 2010 #2

    rock.freak667

    User Avatar
    Homework Helper

    When in parallel, what is the total capacitance?

    How do you find the energy stored in a capacitor?
     
  4. Mar 30, 2010 #3
    Thank you so much!
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook