2002-07-13 Prefixing a unit, does not make it a different unit. The energy unit is still the joule. The prefix just eliminates large numbers to small one by eliminating zeros.
John ----- Original Message ----- From: "Wizard of OS" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Cc: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Saturday, 2002-07-13 11:35 Subject: [USMA:21028] Re: Fwd: Energy unit TWH > which matter would it make if enegry will be saled in MJ?? > > I guess no one! > ----- Original Message ----- > From: "James R. Frysinger" <[EMAIL PROTECTED]> > To: "U.S. Metric Association" <[EMAIL PROTECTED]> > Cc: "U.S. Metric Association" <[EMAIL PROTECTED]> > Sent: Saturday, July 13, 2002 5:17 PM > Subject: [USMA:21025] Re: Fwd: Energy unit TWH > > > > kilopascal wrote: > > > > > > 2002-07-13 > > > > > > The terawatt-hour is not an SI unit. There is only one SI energy unit, > the > > > joule. The terawatt-hour is a combination of an SI unit, the watt and > the > > > non-SI time unit, the hour. > > > > > > The watt-hour is a unit accepted with limited use along with SI, but it > in > > > itself is not SI. > > .... > > > > John, > > > > I have to disagree with you here. The joule is a specially named derived > > unit provided for energy. But other derived units, without special > > names, can be and are used to express quantities of energy, such as the > > newton meter, the watt second, the pascal cubic meter, and so on. > > > > Marvelously, due to the coherence of the system, the numerical factor > > that relates each item in that short list above to the joule is "1". > > Since the hour is accepted for use with the SI, the watt hour can be > > used to represent quantities of energy, but since the hour is not a > > coherent unit within the SI, the conversion factor is > > 1 W.h = 3.6 kJ > > with the period on the line in W.h representing the raised dot for > > multiplication. > > > > Jim > > > > -- > > Metric Methods(SM) "Don't be late to metricate!" > > James R. Frysinger, LCAMS http://www.metricmethods.com/ > > 10 Captiva Row e-mail: [EMAIL PROTECTED] > > Charleston, SC 29407 phone: 843.225.6789 > > >
