Jim, My definition of "weighing" (or to weigh) is "the precess of balancing forces (newtons), usually for the purpose of measuring the mass (grams or kilograms) of an object."
A spring balance (of forces) may be used. The spring must be calibrated for its particular location if it is to display units of mass accurately. An equal-arm (or even an unequal-arm) balance of forces may be used for a more direct measurement of mass by comparison with "standard masses" on one side of the balance. My position is that the term "weighing" (or to weigh) for the purpose of measuring mass is fully compatible with SI. The results, if displayed in grams or kilograms, should be called *mass*. Grams and kilograms should not be called weight if usage is to be compatible with declarations of the CGPM and NIST. Do you accept each the statements above for teaching SI? Which, if any, do you contend is "more pure SI" than declarations of the CGPM or NIST, and not appropriate for teaching SI? As a retiree, I have the time to engage in these exchanges if for nothing more than maintaining a level of brain activity. Gene. ---- Original message ---- >Date: Mon, 26 Jan 2009 20:01:24 -0600 >From: James Frysinger <[email protected]> >Subject: [USMA:42613] Re: The real physics (was Small item seen on TV) >To: "U.S. Metric Association" <[email protected]> > > >It's amazing how we can get wound up on some hot topics around here. (My >personal sore spot tends to be on getting the laws of physics right.) > >I have no qualms about you telling your doctor that you weigh 104 kg. >You have NIST SP 811 on your side regarding the use of "weigh' as a verb. > >Of course, some folks here have a vision of SI that is much more pure >than NIST's or even CGPM/CIPM's. > >Jim
