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Homework Help: How to work out Electrical Energy

  1. May 13, 2010 #1
    1. The problem statement, all variables and given/known data

    Can you please give me some questions and I will see if I can work out the electrical energy?

    2. Relevant equations

    This is what I am going to be working from (Please tell me if it's not correct):

    Energy = Power x Time OR E=Pt
    Power = Current x Voltage OR P=IV
    Substitute
    Energy = Current x Time x Voltage OR E=ITV


    3. The attempt at a solution
    N/A
     
  2. jcsd
  3. May 13, 2010 #2

    mgb_phys

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    Science Advisor
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    Yes thats correct

    ps. In electrical stuff you generally use 'Q' for energy, because E can also mean voltage or electric field in some equations
     
  4. May 13, 2010 #3
    Thanks for verifying, but can you give me any scenarios (questions) where I can use the formula to work out the answer?
     
  5. May 13, 2010 #4

    mgb_phys

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    Electric water heater?

    You have 230V and 13Amps, how much energy/sec does it put into 1kg of water?
    How long does it take to heat 1kg of water form 20C to 100C ?
     
  6. May 14, 2010 #5

    Borek

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    Staff: Mentor

    Less than 2 minutes.
     
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