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Homework Help: Electrochemical cell

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

    A 75.0-W light bulb is powered by connecting it to a standard 12.0 V auto lead-storage battery. How much energy (J) is required to keep the bulb burning for 50.0 continuous minutes ?
    Assume 100 percent efficency.


    2. Relevant equations

    1 watt = 1 J/s
    1 J = 1 C x 1 V

    3. The attempt at a solution

    (50min/12v)(60second/min)(75J/second)

    I am confused about how to get Joules by itself
     
  2. jcsd
  3. Apr 15, 2010 #2

    Redbelly98

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    Welcome to Physics Forums.

    Use the fact that 75.0 W is 75.0 J/s. If you can do something to cancel the s in 75.0 J/s, you will have the energy in Joules.
     
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