KB Posted July 25, 2006 Report Share Posted July 25, 2006 No your reading it wrong it's the 3 and the 'e' that need to rhyme. Ken Link to comment Share on other sites More sharing options...
Pugwash Posted July 25, 2006 Report Share Posted July 25, 2006 No your reading it wrong it's the 3 and the 'e' that need to rhyme. Your differentials may be excellent, but your poetry isn't. Rhyme one (da DA da da da da da da) Rhyme one (da DA da da da da da da) Rhyme two (da DA da da da) Rhyme two (da DA da da da) Rhyme one (da DA da da da da da da) Sorry... next time I'll remember to use monosyllabic words and symbols for the benefit of you Continentals. Scuze me. As long as they're spelt and pronounced right, sure. Link to comment Share on other sites More sharing options...
Pugwash Posted July 25, 2006 Report Share Posted July 25, 2006 Fair enough, but isn't Spelt the monosyllabic term for Triticum Aestivum Spelta? Link to comment Share on other sites More sharing options...
KB Posted July 25, 2006 Report Share Posted July 25, 2006 Bob a small correction is needed.....................I'm the second person ever to get that right Ken Link to comment Share on other sites More sharing options...
KB Posted July 25, 2006 Report Share Posted July 25, 2006 As with all Mathematics you need to solve the problem in stages, my stages were... (1) Log in to old RWG (2) Search for member Nanuq (3) Scroll down the profile tab and click 'Find Topic's' (4) Click on Mathematical problem........................................... And yes I am the perfect bar steward Ken Link to comment Share on other sites More sharing options...
Pugwash Posted July 25, 2006 Report Share Posted July 25, 2006 And yes I am the perfect bar steward ...which is how an Aussie would not spot the Zee/Zed issue. Link to comment Share on other sites More sharing options...
KB Posted July 25, 2006 Report Share Posted July 25, 2006 ...which is how an Aussie would not spot the Zee/Zed issue. Sore loser Ken Link to comment Share on other sites More sharing options...
Pugwash Posted July 25, 2006 Report Share Posted July 25, 2006 Sore loser You know, I can live with that Link to comment Share on other sites More sharing options...
KB Posted July 25, 2006 Report Share Posted July 25, 2006 And besides, I cheated it's Nanaq who has the bad ryhming limerick <---- Chicken Licken Ken Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 Limerick now available from Nanuq's Mug Emporium I know Puggie will be jumping on this one, so get in quick! Here we go: It is a well known fact that metal expands under heat. If you held a solid piece of iron that is in the shape of a doughnut over extreme heat, will the hole in the centre of the iron doughnut grow larger, smaller, or will it remain the same? (And perhaps a brief why!) Link to comment Share on other sites More sharing options...
KB Posted July 26, 2006 Report Share Posted July 26, 2006 I was going to say smaller too, but I'm glad that Nanuq gave the why Betcha you wont find that answer on your card Ken Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 Betcha you wont find that answer on your card Ken That's actually NOT the answer on the card! Obviously Nanuq sounds pretty informed (!) - if I might hazard a guess as to the discrepancy, it's that he's talking about the doughnut shape in mathematics (where it can expand in different ways), whereas this is the observed behaviour of molecules (expansion under extreme heat). Could that be right? Anyway - question is still open.... Link to comment Share on other sites More sharing options...
KB Posted July 26, 2006 Report Share Posted July 26, 2006 Ok then the hole grows smaller because the metal expands in all directions. Ken Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 Ok then the hole grows smaller because the metal expands in all directions. Ken The answer isn't smaller! Or are we heading into "it looks like it melted" territory....?! Link to comment Share on other sites More sharing options...
KB Posted July 26, 2006 Report Share Posted July 26, 2006 Ok then the answer must be bigger because metal expands from the center outwards That better be it because I'm plum outa guesses Ken Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 There's a slightly better answer out there - I'm tempted to leave this one out there, at least for a bit! (OT: I missed out on the cheap Jetstar tickets! Damn crappy website. Bugger!) It is a well known fact that metal expands under heat. If you held a solid piece of iron that is in the shape of a doughnut over extreme heat, will the hole in the centre of the iron doughnut grow larger, smaller, or will it remain the same? (And perhaps a brief why!) Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 (edited) Wow! Interesting subject! But aren't you still thinking of the doughnut / ring as a solid mathematical object? In an iron ring, it is a collection of molecules. So to visualise, say, instead of the solid line in your diagram, there might be strings of dots. What happens if you heat a straight rod? Does it expand equally in width and length, or does is expand more in length? Bend that rod into a ring and heat it. What happens then? Edited July 26, 2006 by cornerstone Link to comment Share on other sites More sharing options...
KB Posted July 26, 2006 Report Share Posted July 26, 2006 Ok I'm reading you now, because the metal expands at a quicker rate lengthwise than what it does either by width or depth then yes of course the center must get larger. Much like getting a wedding ring enlarged Ken Link to comment Share on other sites More sharing options...
Pugwash Posted July 26, 2006 Report Share Posted July 26, 2006 The inner circle will get smaller as the overall diameter T gets larger, proven two ways: I'll give you an observable watch-related proof. If you get a cold SS watch from your watch box, it's loose. Wait for it to warm up, it's not as loose. Quid Est Demonstrandum. Link to comment Share on other sites More sharing options...
Pugwash Posted July 26, 2006 Report Share Posted July 26, 2006 As the purple metal expands at a constant/isotropic rate, point C will move vertically upward from the x-axis at a rate E (for Expansion). By the way, are you sure that it centres on the point in the middle of the torus? That's not the centre of mass. The centre of mass is further out. Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 Great work! Victory to Ken on that one! Not sure if Nanuq and Pugwash are with me yet with this one though....the hole will get bigger as the iron doughnut expands as it keeps the same proportions. And as its sides are longer than its thickness, these grow more. (So in a sense, as much as the thickness increases, in terms of the size of the hole, it is always proportionally outdone by the length.) You can see this with opening a stubborn lid on a jar. If you heat the lid under hot water the lid expands (including the inner circumference) allowing it to be removed more easily. (And, of course, if the hole did get smaller - running the lid under a hot tap would make it tighter) Anyway, while we're settling that - here's different type of question to keep the grey matter ticking over... John Johnson and his new bride Jane, were racing down a country road towards the city. Suddenly John's car began to splutter and cough, and finally stalled. Realising he was out of petrol John decided to go for help. Before leaving he instructed Jane to lock all four doors and keep the windows rolled up tight. John returned to his car to find his bride dead and a stranger in the car. The windows and doors were still locked and closed and the car undamaged. How did Jane die, and who was the stranger? Link to comment Share on other sites More sharing options...
Pugwash Posted July 26, 2006 Report Share Posted July 26, 2006 John Johnson and his new bride Jane, were racing down a country road towards the city. Suddenly John's car began to splutter and cough, and finally stalled. Realising he was out of petrol John decided to go for help. Before leaving he instructed Jane to lock all four doors and keep the windows rolled up tight. John returned to his car to find his bride dead and a stranger in the car. The windows and doors were still locked and closed and the car undamaged. How did Jane die, and who was the stranger? Can you call a newborn baby a stranger? Link to comment Share on other sites More sharing options...
Pugwash Posted July 26, 2006 Report Share Posted July 26, 2006 You can see this with opening a stubborn lid on a jar. If you heat the lid under hot water the lid expands (including the inner circumference) allowing it to be removed more easily. A lid is not a torus. A lid has ... um, a huge slug of metal across the top to stop the jam coming out. It's the top that pushes the edges out. Link to comment Share on other sites More sharing options...
KB Posted July 26, 2006 Report Share Posted July 26, 2006 Can you call a newborn baby a stranger? Yeah it's the only thing that add's up..........Jane died in giving birth, the stranger of course is the baby as it's the first time that John has set eye's on him/her. Tragic really if only John had remembered to juice up the car, they would still be one little happy family, but alas John will now have to raise the child without the help of his beautiful bride. The child on the other hand will turn out maladjusted for not having the Mothers influence and will run away from home at the tender age of 14 never to be seen again, leaving John to die a sad and lonely man..............and all because he was trying to make it to the next town where he could use his shopper docket to get 2 cents a litre off the price of his fuel. Is that the answer on the card Ken Link to comment Share on other sites More sharing options...
cornerstone Posted July 26, 2006 Author Report Share Posted July 26, 2006 Can you call a newborn baby a stranger? Yes, I guess you can! The card says that the woman died in childbirth, and the child was the stranger. With the jar lid, it was more supposed to be an example of how the metal expands proportionally. I found this explanation of the whole hole thing here: http://physics.bu.edu/~duffy/py105/Temperature.html Thermal expansion : expanding holes Consider a donut, a flat, two-dimensional donut, just to make things a little easier. The donut has a hole, with radius r, and an outer radius R. It has a width w which is simply w = R - r. What happens when the donut is heated? It expands, but what happens to the hole? Does it get larger or smaller? If you apply the thermal expansion equation to all three lengths in this problem, do you get consistent results? The three lengths would change as follows: The final width should also be equal to the difference between the outer and inner radii. This gives: This is exactly what we got by applying the linear thermal expansion equation to the width of the donut above. So, with something like a donut, an increase in temperature causes the width to increase, the outer radius to increase, and the inner radius to increase, with all dimensions obeying linear thermal expansion. The hole expands just as if it's made as the same material as the hole. Here was another way of putting it that I found on an ABC discussion forum: The hole would get larger. The way to think about it is as follows. If the plate had no hole in it, the whole plate would expand(as expected). All components of the plate would also incease in size. If you cut a hole into the plate, the disc associated with the hole, would also expand when heated. As this disc must still be able to fit in the hole after heating, the hole must also increase in size. I don't know much about the details, just copying and pasting Link to comment Share on other sites More sharing options...
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