N does not easily transpose to $/m (the bottom line) without a step backward. Stay with J/m and then $/m.
---- Original message ---- >Date: Thu, 10 Jul 2008 21:00:12 -0700 >From: "J. Ward" <[EMAIL PROTECTED]> >Subject: [USMA:41392] Newton for automobile efficiency >To: "U.S. Metric Association" <[email protected]> > > Perhaps newtons could be useful for energy > consumption of automobiles. It would be a way to > compare vehicles with different technologies, such > as gasoline, diesel, electric, hydrogen, etc. I've > seen electric vehicles advertised with their > "efficiency" expressed in miles per gallon. I > assume this is calculated by considering the > chemical potential energy of gasoline if burned in > oxygen. It seems sad to start with a motor whose > mechanical and electrical powers are measured in > kilowatts, with batteries supplying electricity > measured in amperes and volts, and then to > bastardize these standard units into units of > equivalent gallons of gasoline. The results are > also misleading since the efficiency of the power > generation were not taken into account, e.g., how > much coal was used to drive a certain distance? > Anyway, I would prefer to use newtons over > generically measuring energy in units of gallons of > gasoline. Reminiscent of the dreaded BOE.... > > J.
