A test of your common sense

Only because Taz demanded that we attempt to solve the problem using 'common sense'.

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Taz in Message 26:

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And also don't try to insert math or engineering principles. The point of this thread is common sense. Just by looking at it, where does your common sense tell you the beam/plank/piece of wood/person/car/whatever will fail?

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When folks tried to tell Taz that their common sense told them the problem was unsolvable without more informationspecifically, knowledge of engineering (Message 27) and inquired as to how common sense had anything to do with the solution of the problem, Taz again insisted that folks give the problem a try using just their common sense:

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Taz in Message 32:

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Tangle writes:

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Um, what has common sense got to do with it?

It's got everything to do with it.

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Taz wants to make a silly point, and few people here want to be a part of his example. I can't blame them. And that's not Taz's point. Taz's point, in his own words, was that common sense gives a different (and typically wrong) answer to problems than good ol' fashion science and critical thinking: "On the one side, we have honest to god scientists saying one thing and we have ordinary people saying another, using their common sense to try to stump scientists." (Message 32)But everyone participating in this thread already knows that (Message 61, for example), and has told Taz that. Yet he demands we all present evidence to help convince ourselves of something we already believe to be true. Real strange, and not something I'll waste any more time doing.Jon

Given that this thread has been going for four days, and that several people have put forward their common sense solutions that it will fail first either in the middle, at one or both of the points where the force is applied, or at the ends; I'm unclear why we haven't yet been presented with the actual answer to inform us how wrong we all were. Will this happen at any point soon, or should we all just stop reading now?

Well, common sense doesn't tell one the conventions of engineering diagrams, such as whether the beam merely rests on the triangle or is attached to it. Your subsequent explanation with the fat women and the two mental patients makes the problem clear in a way that your diagram does not, except to specialists.

I have been reading this for a while. My first reaction was that I didn't really have a clue, didn't really know the meaning of the triangle and the circle. My common sense dictated that every answer I would give would be most likely dead wrong and would prove some kind of point to Taz, and that it's best to wait for more information.What does confuse me mostly is that it wasn't certain common sense or specific knowledge was needed. Or, by the looks of it, the common sense to recognize you lack knowledge. *sigh* Semantics and riddles, partners in crime.

Seems you are still misrepresenting what I posted.Did you look at the OP?Did you read the OP?Do you read what you write?That the drawing represents a beam, catwalk, stadium seats, bridge or any of a dozen or more other objects is irrelevant to the questions asked in the OP.The question in the OP was, and my response was, This is not a matter of semantics, it is a reply to the question. Very few people deal with how a bridge is supported or the variations of support attachments in a Ames chair, they sit on it or cross it.Everyone in this discussion recognized that the diagram represented a bridge (or similar) but that was not the question asked, was it?

The drawing is not without meaning.
You are without knowledge.

Edited!Taz,I think by now it's pretty clear that lots of us felt the question didn't do quite what you intended it to do.I totally agree with the premise though, I just think that the actual example caused us too many problems for you to demonstrate it properly.Or maybe we're just a bunch of nick-picking, pedantic, argumentative tossers. (Actually, it's not an either or choice ;-)Anyhoo - what's the bloody answer?!Edited by Tangle, : wrong suspect arrested

Eh? Jar didn't ask the original question..
I think you've got some wires crossed...

Ok, why don't we play it by your way.On the left side, the beam is held by a pin to prevent it from moving horizontally but allow it to rotate. On the right side, it is held up by a roller.The beam is a 3 by 5 normal weight concrete (150pcf) reinforced with 3#4 steels (that number just came out of my ass).We have a machine that assert 2 points of equal force at the locations given. The test machine is connected to a computer that has been programmed to increase the load until failure. The program was written in c++. Computer was manufactured by IBM. Test done in standard atmospheric pressure starting at noon. Test performed by a homosexual.When the beam finally fails, where do you expect to see the location(s) of failure?What else do you need to know?

Bugger, you're right - I'll delete.

The bloody answer!Edited by Tangle, : No reason given.

Common Sense tells me that I don't know where the beam will fail.

Taz explains with more detail: And presumably the pin doesn't allow it to move vertically as well. See, I had no idea the triangle was an engineering shorthand symbol for a pin. I still don't have any idea why it was drawn as a Right Triangle facing the way it is instead of an isosceles triangle - what is engineer's fleshing out of that shorthand symbolization? Does it make a difference if the symbol is drawn facing the other way?Now I am reminded of those elasticity/viscosity diagrams with short symbols for various kinds of forces, like a piston symbol for viscosity, arranged in a drawing similar to a software flow diagram.So now I would revise my hipshot answer, since only the roller can move away, once the deformation is large enough. But I need to know if the P on the right is fast enough in acceleration to keep up pace of applying force P on the beam after it slips off the roller. If so then the fat lady on the right will be the first to experience the break, followed by it breaking under the fat lady on the left, only because the radius arm on the right hits the ground first, at a faster speed, providing a bigger jolt to the load P on the right.But if the beam breaks before it slips off the roller, then you have the beam breaking simultaneously under each fat lady.Still not convinced of any thing, though, because this is me trying to use the well-known error-prone common sense to make a hipshot, rather than some more careful scientific analysis.

That is what we needed to know. What was the strange thing on the left side meant to represent? Once you've told us that this strange triangular thing means that "the beam is held by a pin to prevent it from moving horizontally but allow(s) it to rotate" then we can start thinking about the question. Until then, we can't even begin to guess at the answer, 'cos we need to guess at what the triangular thing means.You've conflated two completely different questions. One is a question about physics, the other is a question about what a technical specialist in a particular field means when he draws a triangle and a circle. You can't test people's common sense until you've explained that to them, any more than you can test our common sense about a question phrased in Russian until you've translated the question from Russian into English. Common sense does not provide a right or a wrong answer to the question Когда?

The point that you're trying so ineptly to make seems to be that creationists put their commn sense above the expert knowledge of professionals trained in the field.Nobody here is doing that. We're not denying the expert conclusion. We don't know what it is. If you told us the answer and we rejected it in favour of our commn sense, then your point would be made.What you're doing is the equivlent of laughing at creationists for not understanding evolution and at the same time, refusing to tell them anything about evolution.