hes@ecsvax.UUCP (Henry Schaffer) (12/04/85)
This is an old two part riddle. I) Which weighs more, a pound of feathers or a pound of gold? II)Which weighs more, an ounce of feathers or an ounce of gold? --henry schaffer
hes@ecsvax.UUCP (Henry Schaffer) (12/13/85)
> > This is an old two part riddle. > > I) Which weighs more, a pound of feathers or a pound of gold? One pound of feathers weighs 453.59 grams. One pound of gold weighs 373.2 grams. > > II)Which weighs more, an ounce of feathers or an ounce of gold? One ounce of feathers weighs 28.35 grams. One ounce of gold weighs 31.103 grams. > > --henry schaffer For many years I have been afraid that this riddle would become outdated - but I have feared for naught - it doesn't look as if we will ever go metric. --henry P.S. Don't blame me, this is the way these things are weighed and sold in standard commercial circles.
darin@ut-dillo.UUCP (Darin Adler) (12/18/85)
<> > Have I missed something? Grams and pounds are both units of the same thing - > feel free to call it FORCE if you wish. The "puzzle" makes use of the wild > inconsistencies of "English measures", with different sized ounces and a > different number of those ounces in the corresponding pounds. So what's the > problem? You most assuredly have missed something. Grams are a unit of *mass*. This is a measure of the amount of "stuff". Porunds are a unit of *force*. This is a measure of how hard something is "pushed" or "pulled". When we talk about the *weight* of an object, (measured in pounds, or the metric unit, newtons) we talk about the amount of force that gravity exerts on it (due to the proximity of the object with a very large mass, usually the earth). Mass is a constant (ignoring relativity for the moment), while "weight" is dependent on the mass of the object with respect to which you are measuring weight. My favorite example, from when I originally learned these ideas, is that of a space traveller on the Moon. Due to the fact that the Moon has a much smaller mass than the Earth, the traveller would find that objects have a *weight* of about 1/6 of what he is used to. But the *mass* would not change. Thus, even though it would be easier to pick up objects (because there is less force pushing them down), it would be just as hard to push them around (ignoring reduced friction, of course). By the way, the *slug* is a unit of mass in the English system. I am not sure what relationship it has to a quantity of matter which weighs a pound on Earth. (The reason this is posted to net.puzzle and not net.physics is that I think the folks in net.physics probably know all this already.) -- Darin Adler {gatech,harvard,ihnp4,seismo}!ut-sally!ut-dillo!darin "Such a mass of motion -- do not know where it goes" P. Gabriel
jeff@rtech.UUCP (Jeff Lichtman) (12/21/85)
> <> > > Have I missed something? Grams and pounds are both units of the same thing - > > feel free to call it FORCE if you wish. The "puzzle" makes use of the wild > > inconsistencies of "English measures", with different sized ounces and a > > different number of those ounces in the corresponding pounds. So what's the > > problem? > > You most assuredly have missed something. Grams are a unit of *mass*. This > is a measure of the amount of "stuff". Pounds are a unit of *force*. This > is a measure of how hard something is "pushed" or "pulled". > -- > Darin Adler {gatech,harvard,ihnp4,seismo}!ut-sally!ut-dillo!darin There are two units called "pounds". One of them is a unit of force, and the other is a unit of mass. A slug is the amount of mass that would weigh, in pounds, the same as the acceleration wherever you happen to be. For instance, one slug at sea level weighs about 32 pounds. A poundal is the unit of force which will cause a one-pound mass to accelerate one foot per second per second. Therefore, one pound of force equals about 32 poundals, and one slug at sea level equals about 32 pounds of mass. -- Jeff Lichtman at rtech (Relational Technology, Inc.) "Saints should always be judged guilty until they are proved innocent..." {amdahl, sun}!rtech!jeff {ucbvax, decvax}!mtxinu!rtech!jeff