I think a lot of people are confused that there is a difference between mass and weight because in English units both quantities are measured using the same unit and thus most people would think they are the same thing. Whereas in the metric system a kilogram weighs almost 10 newtons, in English units a pound weighs a pound. At least this is how the average man on the street will understand it.
The is also true for dry ounce versus liquid ounce verse troy ounce and for land mile versus nautical miles. I think most people would be surprised that there is a difference between them. Jerry ________________________________ From: James Frysinger <[email protected]> To: U.S. Metric Association <[email protected]> Cc: U.S. Metric Association <[email protected]> Sent: Monday, February 23, 2009 7:11:00 PM Subject: [USMA:43249] Re: discussion of Food Marketing Institute objections to metric-only labeling option The amount of force exerted is directly proportional to the mass of the object being weighed on a scale. It is also directly proportional to the local value for the acceleration due to gravity (roughly 9.8 N/kg or 9..8 m/s2) The readout is inscribed or computed to read out in units of mass. Moving a scale from one location to another may require require recalibration of that marked-up scale or computation in the case of high-accuracy scales, due to differences in the local value for the acceleration due to gravity. W=mg Jim Carleton MacDonald wrote: > When you buy something in the produce department you put it on the scale, > which measures the force that gravity exerts on what you are buying ... > > Carleton > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf > Of [email protected] > Sent: Monday, February 23, 2009 13:35 > To: U.S. Metric Association > Subject: [USMA:43247] Re: discussion of Food Marketing Institute objections > to metric-only labeling option > > > Carleton, > > Grocery stores sell products by mass, by volume, or by count. > > They may call mass, volume, and count by other names (residue from the > nineteenth century) but in SI they are mass, volume, and count. > > Weight (a force in SI) is *not* an object which can be bought and sold. > > Gene. > > ---- Original message ---- >> Date: Mon, 23 Feb 2009 17:28:59 +0000 (UTC) >> From: [email protected] Subject: [USMA:43244] Re: discussion of Food >> Marketing Institute objections > to metric-only labeling option >> To: "U.S. Metric Association" <[email protected]> >> Cc: "U..S. Metric Association" <[email protected]> >> >> Most grocery stores sell produce by weight. But go >> out to a country Farmer's Market and you'll find the >> tomatoes, apples, etc. in these little bags or >> baskets, all priced by quaint measure such as >> "pint", "quart", "peck", "bushel", etc. > > > > -- James R. Frysinger 632 Stony Point Mountain Road Doyle, TN 38559-3030 (C) 931.212.0267 (H) 931.657.3107 (F) 931.657.3108
