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Post by ironhold on Nov 8, 2015 1:42:13 GMT
This is a catch-all for myths from the funny pages. ** "Henry", 7 November 2015 - Attachment DeletedThis is a similar premise to the "bird toppling a car" myth from a few years ago. A young boy (say 10 or so) is sitting at one end of a canoe (likely wooden) when birds begin to sit in the other end. In time, the weight of the birds is enough to lift the boy's half of the canoe out of the water. |
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Post by GTCGreg on Nov 8, 2015 2:04:30 GMT
The boy must be really light, otherwise why isn't the empty end out of the water before the birds come?
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Post by the light works on Nov 8, 2015 3:04:02 GMT
The boy must be really light, otherwise why isn't the empty end out of the water before the birds come? it's those two bags of concrete he has balancing the canoe. more seriously, I think this would do well with a small scale proof of concept if we can find a small scale canoe. you establish your canoe with a boy analogue so it is balanced - and then add weight to the other end. |
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Post by ironhold on Nov 8, 2015 4:45:23 GMT
The boy must be really light, otherwise why isn't the empty end out of the water before the birds come? it's those two bags of concrete he has balancing the canoe. more seriously, I think this would do well with a small scale proof of concept if we can find a small scale canoe. you establish your canoe with a boy analogue so it is balanced - and then add weight to the other end. Find? Someone with the appropriate skills could maybe make one from a thick paper stock or aluminum foil. We could then have a small artist's mannequin or action figure (preferably one that won't get recognized if the experiment gets filmed) as the analog. |
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Post by the light works on Nov 8, 2015 5:33:06 GMT
it's those two bags of concrete he has balancing the canoe. more seriously, I think this would do well with a small scale proof of concept if we can find a small scale canoe. you establish your canoe with a boy analogue so it is balanced - and then add weight to the other end. Find? Someone with the appropriate skills could maybe make one from a thick paper stock or aluminum foil. We could then have a small artist's mannequin or action figure (preferably one that won't get recognized if the experiment gets filmed) as the analog. I guess that leaves me out. |
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Post by silverdragon on Nov 8, 2015 8:37:09 GMT
Do not try that with a fibreglass canoe.... their extreme lightweight build, a person sat on one end could snap the thing in two?...
On knowledge of small boat build, if the buoyancy of the canoe is not being used in the water, the weight required to lift that person out of the canoe has sunk the other end already?...
As in, if the total load carrying capacity of a canoe was to shift to one end, it would sink.
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Post by the light works on Nov 8, 2015 16:16:54 GMT
Do not try that with a fibreglass canoe.... their extreme lightweight build, a person sat on one end could snap the thing in two?... On knowledge of small boat build, if the buoyancy of the canoe is not being used in the water, the weight required to lift that person out of the canoe has sunk the other end already?... As in, if the total load carrying capacity of a canoe was to shift to one end, it would sink. one of our older canoe manufacturers built canoes to withstand anything nature could throw at it. in a "toss it off the cliff and climb down after it" sense. they were also rather heavy, so it would take a significant amount of weight to unbalance it. I think we want something that is midway between. I know weight shift can bring one end of a boat out of the water - it is standard practice for beaching a hobie. the question is whether the design of a canoe can allow as significant a shift as shown in the comics. |
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Post by ironhold on Nov 11, 2015 8:31:22 GMT
"Archie", 11 November 2015 Attachment Deleted1. Can refrigerator magnets be enough to attach a metal pot to a refrigerator door? 2. Can refrigerator magnets generate enough pull to yank a metal pot in the fashion shown in the strip? |
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Post by silverdragon on Nov 11, 2015 9:00:21 GMT
"Archie", 11 November 2015 View Attachment1. Can refrigerator magnets be enough to attach a metal pot to a refrigerator door? 2. Can refrigerator magnets generate enough pull to yank a metal pot in the fashion shown in the strip? Ask Adam about "rare earth" neodymium magnets...?.... And make sure its not an aluminium or copper pot...... Getting a "ferrous" pot, unless its stainless steel and expensive, is quite hard these days. Frying pans, yes, but most pots of that shape are usually lightweight aluminium based these days?... Unless you spend LOTS. We have reasonable mid-weight Non-Stick coated Aluminium here, easier to clean, but more importantly, "Dishwasher safe". |
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Post by GTCGreg on Nov 11, 2015 14:02:53 GMT
I don't believe stainless steel is a ferrous metal either.
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Post by the light works on Nov 11, 2015 15:12:10 GMT
I don't believe stainless steel is a ferrous metal either. you can get magnetic stainless but it is usually only used for stainless steel refrigerator doors and stainless steel pocketknives. there is magnetic steel cookware available, but you pretty much need to take a magnet shopping with you to tell the difference. that said, I have a torpedo level that is strong enough to stick to the nailheads in sheetrock and support its own weight. - but the strength of a magnet is directly related to the size of the magnet and the thickness of the steel it is grabbing. my level could probably pick up a light steel pan - but whether one of the magnets from it could stick the pan to a refrigerator door is the question. the distance question is very likely a no. if you have old computers with hard disc drives, they typically have nice strong rare earth magnets. |
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Post by GTCGreg on Nov 11, 2015 16:41:49 GMT
I don't believe stainless steel is a ferrous metal either. you can get magnetic stainless but it is usually only used for stainless steel refrigerator doors and stainless steel pocketknives. there is magnetic steel cookware available, but you pretty much need to take a magnet shopping with you to tell the difference. that said, I have a torpedo level that is strong enough to stick to the nailheads in sheetrock and support its own weight. - but the strength of a magnet is directly related to the size of the magnet and the thickness of the steel it is grabbing. my level could probably pick up a light steel pan - but whether one of the magnets from it could stick the pan to a refrigerator door is the question. the distance question is very likely a no. if you have old computers with hard disc drives, they typically have nice strong rare earth magnets. Pure Stainless Steel has a permeability of 1 (totally non-ferrous) Cold working, such as drawing into a pan or bowl shape, or welding can cause it to become slightly ferrous. Your stainless steel pocket knife probably became slightly ferrous because the blade was forged. And you're right about salvaging the magnets out of old hard drives. Just don't use them for fridge magnets. Once stuck, they are difficult to pull off. You almost have to slide them off and that can scratch the paint. |
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Post by the light works on Nov 11, 2015 16:57:48 GMT
you can get magnetic stainless but it is usually only used for stainless steel refrigerator doors and stainless steel pocketknives. there is magnetic steel cookware available, but you pretty much need to take a magnet shopping with you to tell the difference. that said, I have a torpedo level that is strong enough to stick to the nailheads in sheetrock and support its own weight. - but the strength of a magnet is directly related to the size of the magnet and the thickness of the steel it is grabbing. my level could probably pick up a light steel pan - but whether one of the magnets from it could stick the pan to a refrigerator door is the question. the distance question is very likely a no. if you have old computers with hard disc drives, they typically have nice strong rare earth magnets. Pure Stainless Steel has a permeability of 1 (totally non-ferrous) Cold working, such as drawing into a pan or bowl shape, or welding can cause it to become slightly ferrous. Your stainless steel pocket knife probably became slightly ferrous because the blade was forged. And you're right about salvaging the magnets out of old hard drives. Just don't use them for fridge magnets. Once stuck, they are difficult to pull off. You almost have to slide them off and that can scratch the paint. there is a grade of magnetic stainless made specifically for use in making refrigerator doors. there are different explanations why stainless knives are magnetic - one being so that they can be retrieved with magnetic retrieval tools, and another being that magnetic stainless simply works better for them. but considering my meter bases are made with high grade stainless, I can say for sure that my knife isn't just a case of it developing magnetic permeability from being worked. |
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Post by GTCGreg on Nov 11, 2015 17:38:35 GMT
there is a grade of magnetic stainless made specifically for use in making refrigerator doors. there are different explanations why stainless knives are magnetic - one being so that they can be retrieved with magnetic retrieval tools, and another being that magnetic stainless simply works better for them. but considering my meter bases are made with high grade stainless, I can say for sure that my knife isn't just a case of it developing magnetic permeability from being worked. Yes, you can get ferrous SS alloys. It's the other metals in the alloy that give the magnetic properties. Refrigerator doors are not pure SS. They contain a lot of chromium to give them a good appearance. It's the chromium that gives them the magnetic properties. |
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Post by the light works on Nov 11, 2015 17:45:57 GMT
there is a grade of magnetic stainless made specifically for use in making refrigerator doors. there are different explanations why stainless knives are magnetic - one being so that they can be retrieved with magnetic retrieval tools, and another being that magnetic stainless simply works better for them. but considering my meter bases are made with high grade stainless, I can say for sure that my knife isn't just a case of it developing magnetic permeability from being worked. Yes, you can get ferrous SS alloys. It's the other metals in the alloy that give the magnetic properties. Refrigerator doors are not pure SS. They contain a lot of chromium to give them a good appearance. It's the chromium that gives them the magnetic properties. it also lets parents post their children's artwork. |
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Post by GTCGreg on Nov 11, 2015 17:51:19 GMT
Yes, you can get ferrous SS alloys. It's the other metals in the alloy that give the magnetic properties. Refrigerator doors are not pure SS. They contain a lot of chromium to give them a good appearance. It's the chromium that gives them the magnetic properties. it also lets parents post their children's artwork. For sure. Who'd want a fridge that you couldn't stick your kids (or grandkids) pictures or artwork on. To say nothing of the shopping list. |
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Post by silverdragon on Nov 12, 2015 7:51:08 GMT
Ferrous, Made of iron.
Steel, made of iron with some carbon thrown in.
I then ask in the name of sanity, how can Steel be NON-Ferrous?...
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Post by craighudson on Nov 12, 2015 9:24:48 GMT
I surmise that by 'ferrous SS alloys' the poster means ferritic, i.e. body-centred cubic iron. The non-magnetic stuff is austenitic (i.e. face-centred cubic) iron.
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Post by silverdragon on Nov 12, 2015 10:12:59 GMT
Maybe, but its this term that steel can be considered Non Ferrous. Steel is Iron. Iron is Ferrous, "FE" in the periodic table, from the Roman for iron, Ferrum. Therefore, Steel, being MOSTLY Iron, MUST be Ferrum, Ferrous.... I am taking this to an illogical conclusion, so read with a smile.... I therefore ask how it can be "Non Ferrous Steel" And no this isnt a pedantic dig at the posts above, this is a serious question.... that I am taking as a joke on us all, by Scrap merchants... The term Non Ferrous is used in scrap industry to indicate metals that are not magnetic, even if they are steel. [ source www.answers.com/Q/Is_stainless_steel_a_nonferrous_metal as just for one example there are others out there...] I get that its an alloy of chrome Molybdenum, which I am always trying to pronounce moly-bend-i-um, because I can never get it right, nickel, but, its also 75% IRON.... high carbon content steel is still 99% Iron.... So how can it be NON-Iron, in the statement non-ferrous, which indicates its not iron... Thats like saying a pork pie pastry when the pork is taken away is "Kosher", because the pastry is not pork?.. If you get my drift?... If 75% of an item is something, you cant sort of say its NOT that. This is the type of miss-information in the world that makes it confusing for "sane" people who know the truth... |
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Post by GTCGreg on Nov 12, 2015 13:01:08 GMT
In engineering, we usually referred to nonferrous as also meaning non-magnetic. That's probably incorrect nomenclature. Maybe we should just say non-magnetic instead. But that said, in the scrap industry, they usually separate ferrous from non-ferrous metals by using a magnet. Since stainless steel is not picked up by the magnet, it ends up in the non-ferrous heap.
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