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Homework Help: Power Question

  1. Oct 29, 2006 #1
    This is an A.P Physics class which is algebra based and does not use calculus. This problem is really annoying because it is one of the easier questions from the homework but i can't seem to understand the procedure.

    One kilowatt x hour (kWh) is the amout of work or energy generated when one kilowatt of power is supplied for a times of one hour. Determine the number of joules of energy in one kilowatt x hour.

    Any suggestions?
  2. jcsd
  3. Oct 29, 2006 #2
    This question is just asking you to do a simple unit conversion using the definition of power. As you know from the problem, kiloWatt*Hour is an unit of Energy and you have to convert this unit into Joules.

    So you have
    kiloWatt*Hour = 1000*Watt*Hour = 1000*Watt*(3600 Second)

    Now you know that Watt = Joules/Second

    Then you get
    1000*Watt*(3600 Second) = 1000*(Joules/Second)*(3600 Second) = 3.6E6 Joules (in scientific notation).
  4. Oct 29, 2006 #3
    Thank you Swapnil
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