John wrote in USMA 11097 >The so-called pound-mass vs. pound-force vs. pondual is so confusing, please >keep this confusion out of SI. SI is an absolute system. We don't need >units like kilogram-force when we have newtons. Don't waste your brain >energy trying to figure out what a kilogram-force weighs at sea level, on >the top of Mount Everest (8850 m) or on the planet Vulcan. Who cares? > >When ever someone starts talking about kilogram-forces, introduce them to >the proper unit, the newton and explain there is no confusion between the >meanings and values of SI units no matter where they are. That also goes >for "other" non-SI units, whether they be old metric or old fart. Now, >there is a new name for FFU, OFU (old fart units). Remember, don't be a >metric farter, be metric smarter! About 1973 a professor of mechanical engineering at McMaster University, Hamilton, Onrtario, told his class that SI only applied at a distance of 13 600 km above the surface of the earth because it is only at that distance that the force of gravity acting on 1 kg is 1 N. This was told me by a student who knew better, but who kept quiet. Joseph B. Reid 17 Glebe Road West Toronto M5P 1C8 Tel. 416 486-6071
