Rank: Advanced Member Groups: Registered
Joined: 22/09/2009(UTC) Posts: 34 Location: Utah State University, Logan, UT, USA Was thanked: 20 time(s) in 7 post(s)
|
About the definition of pound, lb : the current definition of lb in SMath Studio is 1 lb = 0.4536 kg. In the U.S., where the so-called "Imperial," or "English," system of units refuses to leave center stage, the pound, lb, is a unit of force, not of mass. Some unit-conversion software, such as the one included with the HP graphing calculators, use 'lbf', i.e., pound-force, to refer to the pound as force, and then use the 'lb' to refer to the pound as mass, as you do. I would suggest adding the pound-force 'lbf' in SMath Studio, with 1 lbf = 4.44822161526 N. Including the pound-force, as I suggest, will allow us, hydraulic engineers in the U.S., to use the commonly-used unit of pounds per square inch (psi = 1 lbf/in^2) for pressure, which currently I cannot properly define. If you decide to include 'psi' in your collection of units, use 1 psi = 6894.75729317 Pa. I also use the psf = pound-per-square-foot, 1 psf = (1/144) psi = 47.8802589803 Pa. By the way, the unit of mass in the English System ( E.S. ) is the 'slug', 1 slug = ( 1 lbf )/(1 ft/s^2). The "slug" should be included in the units of mass in SMath Studio also. 1 slug = 14.5939029372 kg. Also, the BTU, or Btu, (British Thermal Unit) should be included in the units of energy, since is still commonly found in HVAC applications. 1 BTU (or Btu) = 1055.05585262 J. Thanks to Andrey, again, for implementing units in SMath Studio. That'll make my life much easier! Gilberto Urroz Edited by user 09 March 2010 21:02:44(UTC)
| Reason: Not specified
|