studiot

Have you read all 9 now 10 pages of this thread or would you like me to list all the evidence I have posted in this thread? You owe me an apology

A typical troll, doing exactly what he accuses someone else of doing. Where is your evidence for your underlined words?

Naw man, my fault for not using the correct language to fully convey my meaning. I need to work on that. Well ignoring your picture what about commenting on the rest of my post? This did, after all, address your topic.

Interesting point, but I don't think the condition of the utterer affects the truth value of the proposition any more than the conditions (eg timing) of the utterance. I agree with Reg here. except to be strictly pedantic the truth value is unaffected.

So you should have no trouble answering my two polite propositions as true or false.

Yup +1 Oh, and by the way, Reg Are you frightened of my examples?

Like others here, I am a bit mystified understanding what you are trying to do. In terms of pure plane trigonometry, (no higher maths needed) can you answer the following question. Are you aware that sometimes the sine rule in plane triangles is ambiguous that is there can be two different solutions to certain triangles when using the sine rule ? That is why it used to be taught (I fully sympathise with wtf's comment on the 'modern' syllabus) in schools to use the cosuine rule which is never ambiguous. Does this help any ?

I like the computing viewpoint and the introduction and use of the word policies. +1 The second paragraph falls a bit short of rigour though; acceleration can't be directly compared to speed , they are not the same. You clearly understand that for the most part one cannot demand an 'either/ or' answer. This is a very long thread, perhaps you, like everyone else, missed this post of mine on page 7. Did you have any thoughts on the truth of the statements it contains and their connection to knowledge? In particular, because I have the means of calculating the length of a pendulum of period 1 second does that mean I have the knowledge of that length? Or because I have a book of sine tables and a calculator so I can look up the value of any desired sine, again does that mean I have the knowledge of the value of that sine? Check the actual post as this stupid forum will not reproduce the formulae faithfully when copying or quoting.

If you want to quote Mathematics, you shouldn't wonder you should know. Further the author of zillions is hiding in plain sight in the thread.

This is nonsense and you know it. It's like saying, "Every time a woman runs for the office of the president of the United States, she is defeated. Every time. EVERY TIME. Can we use these observation (sic) to predict that next year, when a woman runs for president, she will be defeated?" Well, of COURSE you can make that prediction. Will that prediction be true? You have no idea. If you can't tell the difference between a few trials (or even zero trials) and many trials in a statistical experiment then your knowledge of Mathematics is seriously defective. So I suggest you refrain from such contemptuous and discourteous remarks about the thoughts of others as with this example and your shallow unthinking comments om post whilst I was away.

Hello Philip and welcome.# A few pointers to forum etiquetter first. You seem to say that this is coursework so it should be in the Homework section. Please read the rules of this section here. As regards to your question well you have mentioned the concentration of hydrogen peroxide, but what about the concentration of potassium iodide? What else should you mention? Well I suggest you use the full names in the paper rather than the symbols. Then think about what conditions can vary. (eg temperature, pH......) What do you know about the reaction? That is what are the products? What are you going to measure to gauge the rate? Will the reaction go to completion ? How will you know? What happens if you have a large excess of one reagent?

How is this on topic?

You quote an equation. and say it is due to Einstein. I agreed that Einstein wrote the equation and found the actual part of the paper where he wrote it. And you reply by accusing me of a government cover up. ????????????????????????????????????? You also claim this equation is at variance with some other equation writen by "they" , whoever they might be. And yes I also agree that two equations are different. And I have pointed out that these equations refer to the calculation of different quantites, so I don't find it suprising that they are different. The associated personal abuse is neither warranted nor welcome.

OK guys would someone like to analyse these statements and tell me if they are right or wrong, true or false and also if there is any difference between the categorisatiosn right/wrong and true false. The period (T) of a simple pendulum is given by the equation [math]T = 2\pi \sqrt {\frac{L}{g}} [/math] The sine of of 35 degrees is 0.5736.

I have been away for a few day, but i see this topic is still live. The analysis I gave was a classical one using macroscopic variables and what engineers call a 'control volume' which in the limiting case can be integrated. If you wish to construct a kinetic model then instead of using a control volume, you need to use separating or cutting planes (splitting the column into two 'free bodies') and the equilibrium constraint condition. So consider a horizontal cutting plane anywhere across a colum in equilibrium. Since the column is in equilibrium there is no change of composition with time. Time is then the variable of integration. This means that The time average number of molecules passing upwards must be equal to the time average number of molecules passing downwards through the section. If this were not so then gas would accumulate on one side or the other of the cut plane. Since in the simple model all molecules have the same mass, this can be related to the momentum or kinetic energy concerned. The horizontal section is almost the simplest, if we now consider a vertical section we can perform the same analysis. Finally, as is so often the case in this type of analysis we need to consider slant sections at any angle between horizontal and vertical.

Did you read the (impressive) list of proofs that I linked to disputing this?

Actually it does. It is just that the procedure Einstein adopted to ensure this by correct zeroing of the clock was not part of my excerpt. Would you like to see that part or can you look it up for yourself?

Well aren't they?

How can it be full? A full set would include rationals (which have been removed). This is one of pecularities of infinite sets. Between any two rationals there is a real irrational number and Between any two real numbers there is a rational number. Yet there are more irrational numbers than there are rational ones. https://www.google.co.uk/search?source=hp&ei=ojfnW5ayBcOMsAH_naXQAg&q=between+any+two+real+numbers+there+is+a+rational+onumber&oq=between+any+two+real+numbers+there+is+a+rational+onumber&gs_l=psy-ab.3..0i13k1j0i22i30k1l5.2704.20152.0.20460.56.35.0.21.21.0.232.4480.2j29j2.33.0....0...1c.1.64.psy-ab..2.54.4876...0j0i131k1j0i8i13i30k1.0.H9_9tj3QgJU

You missed at least one. Any worthwhile listing of such possibilities will automatically include "some combination of these" Once again pigeonholing fails.

Damn and Blast this site editor. I just lost a significant post it didn't save, like it used to. I will try to reproduce it, but I fear the result won't be half as good. Thank you. A decade (and a bit) before me. Wow. Perhaps you used C J Smith " A Degree Physics" ? I'm sure you know quite a bit about the principles then, even though the connections may be a bit rusty. Fluid statics and dynamcs have the same difference as other parts of mechanics. They use different equations. Fluid statics uses the principles and equations of equilibrium (dynamical equilibrium) for fluids. Dynamics uses Newton's laws along with the conservations laws of momentum and energy. The trick with the analysis of the air column is to know when to use a plane section and when to use a differential section to get volume. I will come back to that. Meanwhile I note you have posted in Earth Science not Physics, so is your interest in this really in Earth Science? Here is an extract from a brilliant book about this from an Earth Science perspective with a much more detailed presentation than my scribbling and provides an explanation (compressibility I took for granted) along with an explanation of why Seifert is just plain wrong. Atmoshere and Ocean - Our Fluid Environments J G Harvey I don't care if he is God Almighty that was bad Physics in reply to a question about the atmosphere.

This is why I advised caution. That equation is incorrect for the atmosphere. The link you gave has some good replies and some dubious ones like the one due to Seifert.

Yippee, progress. Another +1 for that. But please let us have some more feedback for this and any further questions. You say you understood the mathematical development. This is good as I don't care what level you are at, I just want to post that that level. Did you also understand the later post about the difference between fluid statics and fluid dynamics and in particular the bit about shear and normal stresses? If I talk about random walks for molecules would you have heard of these? Finally I note that a few posts back you correctly noted that the conditions for momentum to change, resulting in a force, is when a molecule is what you called reflected ie bounces back from a boundary.

Swansont has mentioned several times that the kinetic theory is the microscopic mechanism and simple newtonian mechanics the bulk theory of fluids. Bearing this in mind we should not let visions of bonny bouncing molecules run away with us responding to the OP question which was about fluid statics, not fluid dynamics. In particular care is needed in considerations of momentum and momentum flux. Momentum flux refers to fluids moving in the bulk and shear stresses. There are no shear stresses in fluid statics, so the OP question was about normal stresses only. Aligning the kinetic theory with fluid statics is actually quite tricky, in some ways more tricky than for fluid dynamics because of this. So we need to take care not to offer confusion to the OP on this matter.