Watts was defined as J/sec

  • Thread starter Pengwuino
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  • #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???
 

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  • #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.
 
  • #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.
 
  • #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
 
  • #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
cepheid
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And it seems I forgot about the "kilo" in my post :redface:
 
  • #8
Pengwuino
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Ah beautiful, now my calculations will make more sense.
 
  • #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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