larry@kitty.UUCP (Larry Lippman) (12/02/85)
> Which weighs more, a liter of wet sand or a liter of dry sand? > -- > Col. G. L. Sicherman > UU: ...{rocksvax|decvax}!sunybcs!colonel Hmmm. Lemme see... Since this is net.puzzle rather than, say, net.physics, this must be a `trick' question. Or is it? Let's look at `liter' first. One liter is the volume of one kilogram of water at 3.98 degrees C (the maximum density point as a liquid) taken at standard atmospheric pressure, and one liter is damn close to 1,000.00 cubic centimeters. While we normally think of a liter for liquid volume measurement, the liter is a valid unit of volume measurement for ANY material in ANY state. So, the use of the term liter is okay and not a trick. Sand in its "pure" form is an anhydrous variety of silicon dioxide. There are many varieties of sand, such as: silica sand, amosil, beach sand, Monazite sand, black sand, engine sand, foundry sand, Grant sand, Tuscarawa sand, etc. While each of these sands has somewhat different characteristics, including a variety of grain sizes, in general they have a specific gravity range of 1.4 to 1.8, so sand will neither float or be otherwise displaced by water. Sand has an affinity for water because silicon dioxide adsorbs water on a molecular level (an amorphous cousin of sand - still silicon dioxide - is silica gel, which is a common dessicant). Not only will sand adsorb water with no increase in volume (over anhydrous sand), but the gross interstitial spaces between the grains of sand will hold even more water. Since sand is far denser than water, the presence of water will in no way displace the sand and increase the volume. Sand saturated with water has an specific gravity range of 1.9 to 2.1, therefore making a given volume of wet sand heavier than a given volume of dry sand. So the only valid answer is that a liter of wet sand weighs MORE than a liter of dry sand. I don't see any problem using the term `wet sand' to denote sand which is saturated with water, as opposed to `dry sand' which is anhydrous. So I don't see a trick here. The above is no doubt overkill, since I was suspicious of a trick; although I'll be damned if I can find one... === Larry Lippman @ Recognition Research Corp., Clarence, New York === === UUCP {decvax,dual,rocksanne,rocksvax,watmath}!sunybcs!kitty!larry === === VOICE 716/741-9185 {rice,shell}!baylor!/ === === FAX 716/741-9635 {AT&T 3510D} ihnp4!/ === === === === "Have you hugged your cat today?" ===
dgary@ecsvax.UUCP (D Gary Grady) (12/04/85)
In article <621@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes: > Let's look at `liter' first. One liter is the volume of one kilogram >of water at 3.98 degrees C (the maximum density point as a liquid) taken at >standard atmospheric pressure, and one liter is damn close to 1,000.00 cubic >centimeters. To my knowledge, this definition was superseded in (around 1970?) by making 1 liter by definition EXACTLY 1000 cubic centimeters. And while we're on exact conversion factors, in the USA an inch is EXACTLY 2.54cm. I'd tell you more but the keeper is coming. -- D Gary Grady Duke U Comp Center, Durham, NC 27706 (919) 684-3695 USENET: {seismo,decvax,ihnp4,akgua,etc.}!mcnc!ecsvax!dgary