From: Peter Irwin on 18 Nov 2009 00:56 In rec.photo.digital J?rgen Exner wrote:> > Not to mention that there is also a liquid ounce which apparently has > nothing do to with the weight ounce. Question: when you melt gold, do > you have to use the liquid ounce now instead of the troy ounce? An Imperial fluid ounce of water weighs an ounce avoirdupois. The US fluid ounce is slightly larger. Gold is bought and sold by troy weight. How you choose to measure it during an experiment is your own business. > And now please tell me again that all this is less confusing and easier > than milligram, gram, kilogram, and tons. > There are a number of handy features. A cubic foot of seawater weighs 64 pounds. David Littleboy's example of the density of seawater in slugs per cubic yard is thus easier than he seems to suggest. Since acceleration due to gravity is around 32ft/s^2, there are two slugs per cubic foot of seawater and thus nearly 54 slugs per cubic yard. The main obvious advantage is that it trains you to do mixed-base mental arithmetic. Peter. -- pirwin(a)ktb.net From: Tzortzakakis Dimitrios on 18 Nov 2009 13:05 ? "Eric Stevens" ?????? ??? ?????? news:vq46g5l3iag3gtemh8228i0o85l2hai2tm(a)4ax.com...> On Tue, 17 Nov 2009 11:37:15 -0500, "Neil Harrington" > wrote: > >>Eric Stevens wrote: >>> On Tue, 17 Nov 2009 02:40:29 -0500, "Neil Harrington" >>> wrote: >>> >>>> Note that the same reason has been suggested for the fact that >>>> British .303 service rifle ammunition was made with bullets having >>>> an aluminum nose cone under the jacket, making the bullet somewhat >>>> tail-end-heavy. Thus the ammunition met the Geneva Conventions >>>> requirements for full jacketed (theoretically "humane") bullets, but >>>> because it was somewhat likely to topple passing through the target >>>> it could actually be more destructive than if it had been soft-nosed. >>> >>> Many years ago I was involved in military target shooting with the >>> British No4 rifle and also Bren guns using the more powereful Mk VIII >>> amunition. We were shooting at ranges between 100 and 800 yards at >>> 6'x6' targets. I saw the holes left by many thousands of 303 ounds and >>> as far as I know they all went straight through the target unless they >>> had first clipped the top of the butt. I never saw any other evidence >>> of a tumbling round. >> >>There wouldn't have been any tumbling *in flight*, only after striking and >>entering some substantial target such as a body. Assuming your targets >>were >>heavy paper (as ours were in the U.S. Army), the bullets would have passed >>straight through leaving only a neat round hole. > > I didn't realise you meant tumbling after impact as I know some > weapons suffer(?) from tumbling in flight and I thought that was what > you meant. >> >>Also, the .303 ammunition made that way was the Mark VII if I recall >>correctly. I have no idea whether that method of manufacturer was still >>used >>with the Mark VIII type. >> > Google is our friend. See http://en.wikipedia.org/wiki/.303_British > for the full story. It confirms that you are right about what the > bullet does after impact. http://en.wikipedia.org/wiki/Hollow-point_bullet See the second photo on the right, "swedish.."etc (about a common ball raound). -- Tzortzakakis Dimitrios major in electrical engineering mechanized infantry reservist hordad AT otenet DOT gr From: Neil Harrington on 19 Nov 2009 17:16 "Bill Graham" wrote in message news:VrmdncXql872857WnZ2dnUVZ_hOdnZ2d(a)giganews.com...> > "J. Clarke" wrote in message > news:hdvdc802dap(a)news2.newsguy.com... >> tony cooper wrote: >>> On Tue, 17 Nov 2009 12:01:52 -0800, J�rgen Exner >>> wrote: >>> >>>> tony cooper wrote: >>>>>> Same happened to me yesterday in the supermarket. Two products, >>>>>> for one the price given in \$/pound, for the other in \$/ounce. How >>>>>> do you compare them on the spot? No, I cannot do a multiplication >>>>>> by 16 in my mind on the spot in front of the shelf, I do need >>>>>> paper and pencil. >>>>>> >>>>>> Using the metric system it would have been trivial, even if they >>>>>> had used different sizes, e.g. \$/kg and \$/100g. Just shift the >>>>>> comma and you are done. >>>>>> >>>>>> Not so with the US units. There a pocket calculator seems to be >>>>>> mandatory for grocery shopping. >>>>>> >>>>> You think? >>>> >>>> No, I don't think, I know. It happened yesterday while I was looking >>>> for fresh steaks in the meat aisle in a Safeway store. >>> >>> This doesn't ring of truth. Fresh meat is priced per pound. All the >>> steaks would be priced per pound. Packages have different prices >>> because they contain different amounts of weight. I can't imagine >>> you'd need a calculator to compare prices. >> >> I've never seen fresh meat packaged other than with the price of the >> package >> and the price per pound on it. >> >>>>> Every supermarket in this area has a shelf tag that gives >>>>> the price per common unit on comparable items. In other words, in >>>>> the cereal aisle, the tags will all show the price per ounce for the >>>>> cereal even if the box is labeled by units other than just ounces. >>>> >>>> And yes, I am talking about the price on the label on the shelf >>>> (which happened to match the pricing unit on the individual article, >>>> too). >>> >>> Perhaps where you are it's different, or perhaps you didn't look at >>> the label carefully. Canned or boxed goods, in this area, can all be >>> compared by ounce price regardless of the weight in the can or box. >>> >>> Here's an example: >>> >>> http://www.ses.wsu.edu/Grants/StoreShelf.htm It shows that Jiffy >>> Peanut Butter is 13.24 cents per ounce. That allows you to compare >>> other brands, and other sizes of the same brand, by cost-per-ounce. >>> No calculator needed. >>> >>> I've used this tag feature and found that the "economy" size is not >>> always the most economical size to purchase. >> >> Dunno about where you are but around here sometimes one tag is in cost >> per >> ounce and another is in cost per pound, on items of the same kind with >> different brands or different package sizes. >> > > Very true.....I remember deciding that paper towels were cheaper when > purchased individually than they were when purchased in packages of three > at our local Safeway. When I pointed this out to the clerk she was not > surprised. I've seen the same sort of thing in other products at my local Stop & Shop. I suppose a lot of people buy the larger packages assuming they're the better buy without actually comparing, even though the store makes it ridiculously easy to make the price comparison. From: Bill Graham on 20 Nov 2009 00:31 "Peter Irwin" wrote in message news:he029n\$bh\$1(a)dns.ktb.net...> In rec.photo.digital J?rgen Exner wrote: >> >> Not to mention that there is also a liquid ounce which apparently has >> nothing do to with the weight ounce. Question: when you melt gold, do >> you have to use the liquid ounce now instead of the troy ounce? > > An Imperial fluid ounce of water weighs an ounce avoirdupois. > The US fluid ounce is slightly larger. > > Gold is bought and sold by troy weight. How you choose to measure it > during an experiment is your own business. > >> And now please tell me again that all this is less confusing and easier >> than milligram, gram, kilogram, and tons. >> > There are a number of handy features. A cubic foot of seawater > weighs 64 pounds. David Littleboy's example of the density of > seawater in slugs per cubic yard is thus easier than he seems > to suggest. Since acceleration due to gravity is around 32ft/s^2, > there are two slugs per cubic foot of seawater and thus nearly > 54 slugs per cubic yard. > > The main obvious advantage is that it trains you to do mixed-base > mental arithmetic. > Not today it doesn't. All the young people carry cell phones that go to the internet and get any conversion they want, and do any arithmetic they need with the press of a few keys. You can tell that they are doing this, because when they make a mistake, they are off by huge factors that defy any and all reason. When I make a mistake in my mental calculations, I know it immediately, because I have some idea of the answer even before I begin. But when you are accustomed to trusting your answers to a machine, you have little choice but to crash and burn when the machine makes a mistake, or you make one when you input the data. From: David Nebenzahl on 20 Nov 2009 01:47 On 11/19/2009 9:31 PM Bill Graham spake thus: > "Peter Irwin" wrote in message > news:he029n\$bh\$1(a)dns.ktb.net... > >> In rec.photo.digital J?rgen Exner wrote: >>> >>> Not to mention that there is also a liquid ounce which apparently has >>> nothing do to with the weight ounce. Question: when you melt gold, do >>> you have to use the liquid ounce now instead of the troy ounce? >> >> An Imperial fluid ounce of water weighs an ounce avoirdupois. >> The US fluid ounce is slightly larger. >> >> Gold is bought and sold by troy weight. How you choose to measure it >> during an experiment is your own business. >> >>> And now please tell me again that all this is less confusing and easier >>> than milligram, gram, kilogram, and tons. >> >> The main obvious advantage is that it trains you to do mixed-base >> mental arithmetic. >> > Not today it doesn't. All the young people carry cell phones that go to the > internet and get any conversion they want, and do any arithmetic they need > with the press of a few keys. You can tell that they are doing this, because > when they make a mistake, they are off by huge factors that defy any and all > reason. When I make a mistake in my mental calculations, I know it > immediately, because I have some idea of the answer even before I begin. But > when you are accustomed to trusting your answers to a machine, you have > little choice but to crash and burn when the machine makes a mistake, or you > make one when you input the data. Time to go back to slide rules, I say. (At least as pedagogical tools, if not for actual engineering use. Although they're still useful in that function as well.) I wonder: how many kids today would have the faintest idea of what they're doing with one (I mean apart from the obvious nerds and geeks)? -- I am a Canadian who was born and raised in The Netherlands. I live on Planet Earth on a spot of land called Canada. We have noisy neighbours. - harvested from Usenet First  |  Prev  |  Next  |  Last