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Watts was defined as J/sec

  1. Apr 13, 2005 #1

    Pengwuino

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    I thought watts was defined as J/sec . So how can something be rated in watts/hour? Doesnt that mean Joules per second per hour???
     
  2. jcsd
  3. Apr 13, 2005 #2

    russ_watters

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    Where are you seeing this? You sure it isn't watt-hours (w * h)? A watt-hour is a joule per second of power - for an hour.
     
  4. Apr 13, 2005 #3

    cepheid

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    I've never heard of anything rated in W/hr. Your electricity meter shows your energy consumption in kWh (kilowatt hours), which would be Jh/s. So clearly one kWh = 3600 J (I hope I did that right). Are you sure the Watts and hours were not being multiplied in the example you saw?

    edit: russ was quicker on the draw.
     
  5. Apr 13, 2005 #4

    Pengwuino

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    I thought like, your electricity bill is measured in KW/H.... is it suppose to be KW*h?? I dont have it written down anywhere, i just always remembered electricity as being generated as KW/H..... have i just been living with a bad assumption for these past few years lol
     
  6. Apr 13, 2005 #5

    Pengwuino

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    lol oh man, so ive been remembering and writing it down incorrectly? lol oh man... im an idiot.

    So 1 KWh, the thing your billed for... is 3.6MJ?
     
  7. Apr 13, 2005 #6

    chroot

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  8. Apr 13, 2005 #7

    cepheid

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    And it seems I forgot about the "kilo" in my post :redface:
     
  9. Apr 13, 2005 #8

    Pengwuino

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    Ah beautiful, now my calculations will make more sense.
     
  10. Apr 13, 2005 #9

    dextercioby

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    There's no physical quantity which would have the (SI) units [itex] \frac{\mbox{W}}{\mbox{s}} [/itex].It would be the rate of variation of power (electrical or mechanical) in unit time,but no one asserted a name to it.

    Daniel.
     
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