Dear Gene, I agree g is a variable and in writing 9.81 we implicitly state that we have an error of 0.005 units. Whether this is correct I am not sure, but the pure maths implicit error still provides a guide. In the same way that 9.99999 is not 10.
John >Date: Fri, 11 Oct 2002 18:07:57 -0500 (CDT) >From: Gene Mechtly <[EMAIL PROTECTED]> >X-X-Sender: <[EMAIL PROTECTED]> >To: "U.S. Metric Association" <[EMAIL PROTECTED]> >cc: <[EMAIL PROTECTED]>, "U.S. Metric Association" <[EMAIL PROTECTED]> >Subject: [USMA:22636] Re: Newton's 2nd Law applied to Water >Reply-To: [EMAIL PROTECTED] >Sender: [EMAIL PROTECTED] > >You forget that g is a variable, not a constant! >........................................ >On Sat, 12 Oct 2002, Wizard of OS wrote: > > > there is no formula w = m g > > > > the only valid formula is from Newton: F = m a > > in our case is a = g > > > > F = m g > > F = 1 kg = 9,81 m s^-2 > > F = 9,81 N > > > > that's it John Nichols BE, Ph.D. (Newcastle), MIE (Aust) Assistant Professor Texas A&M University Department of Construction Science Langford AC Rm: A414 MD 3137 College Station, TX 77843-3137 Electronic mail: [EMAIL PROTECTED] Telephone: 979 845 6541 Facsimile: 979 862 1572 ----------------------------------------------------------------- Magna res est vocis et silentii temperamentum The greatest thing is to know when to speak and when to keep quiet Seneca the Younger (attributed) -----------------------------------------------------------------
