studiot

In the case of the composite rod, pulled in tension at both ends, yes this is correct. So can you now calculate the strain for both pieces and complete the question, including the max stress?

I have only been talking about the question from your other post, which I see now is different from the original question in this thread. I can only deal with one subject at a time.

Now we are getting somewhere. if the youngs moduli (note the plural) are different, how can the stress and strain both be the same? Do you think the stress or the strain or both are different?

And what is your definition of young's modulus?

Is that all? What about the tensile force The stress The strain ?

Sorry but your originals are such a mess I don't know what I got right or wrong, but you posted the following yesterday If you can't get the page all in the other way round copy it out yourself so it fits your phone. Now how about answering the question I asked, which is relevent to the question you posted in the other thread, and I reposted properly here.

Question for you : what is the same and what is different in each of the sections of the composite rod? Why did you not add this to your previous thread question? Please ask a mod to combine the two threads. Edit for those who would like to see the original question

I'm not sure you have fully appreciated my initial offering. The theory of heat engines depends upon working in a cycle. This means that we end up where we started with a mass of working fluid'. That is the working fluid is returned to its initial state. If heat or work is added somewhere in the cycle then it must be removed somewhere else in the cycle. The Brayton cycle is paticularly important to understand as it forms the basis of lots of different types of heat engine. The work integral around the cycle of such a machine is equal to the difference between the heat received at one temperature minus the heat rejected at another. [math]\oint {W = {\rm{Heatreceived}}\;{\rm{ - }}\;{\rm{Heatrejected}}} [/math] Four stages are identified and it is good to work per unit mass of circulating fluid. 1 - 2 : Adiabatic isentropic compression according to the law [math]P{V^\gamma } = C[/math] Pressure increase from P1 to P2 Temperature increase from T1 to T2 Volume decreases from V1 to V2 Entropy remains constant S1 = S2 2 - 3 Constant pressure heat addition This can be caluclated from the heat (enthalpy) of combustion, assuming complete combustion or by applying Cp(T3 - T2) Pressure remains constant at P2 = P3 Temperature increases from T2 to T3 Volume increases from V2 to V3 Entropy increases from S2 to S3 3 - 4 Adiabatic isentropic expansion according to the law [math]P{V^\gamma } = C[/math] Pressure decrease from P3 to P4 Temperature decrease from T3 to T4 Volume increases from V3 to V4 Entropy remains constant S3= S4 4 - 1 Constant pressure heat rejectionThis can be calculated from by applying Cp(T4 - T1) Pressure remains constant at P4 = P1 Temperature decreases from T4 to T1 Volume decreases from V4 to V1 Entropy decreases from S4 to S1 You have been given some of the pressures, temperatures etc and can use these stages to calculate the missing ones and thus answer the questions. Beware that some temperatures are stated in absolute and some in centigrade in your diagram. To test for condensation you then have the PVT within and through the turbine to compare against a state diagram for water.

These things rarely arrive on their own Often good programs like ADW cleaner won't install or run properly. Further no single program kills them all. I have found this French one (Junkware Removal Tool) runs in most circumstances, when others will not. http://www.bleepingcomputer.com/download/junkware-removal-tool/ If JRT followed by ADW Cleaner does not do the trick then the bleeping computer site provides real help in cleanup. When the bad guys are gone run the following Microsoft tools, in this order. Disk Cleanup CheckDisk System File Checker. MSconfig Finally Super Anti Spyware runs well alongside most anti virus so load it when you have finished cleanup, http://www.superantispyware.com/ There is a free version.

You are looking along the right lines, but rather than develop you own version Brayton analysis you should get a solid grasp of the conventional one. The Brayton cycle is also called the constant pressure cycle or the Joule cycle. The first thing to notice is that the machine arrangement as diagrammed is an open system and you need a closed cycle to create an analysis. The idea is to chose a working fluid (air or air/fuel as an ideal gas) and develop a cyclic process involving it. We do this by choosing to consider cycling our working fluid round four stages. (so there is no air input or output) Instead of combustion, heat is considered added from an external source at constant pressure (Cp times the temperature change) in the second stage of the cycle and a different quantity of heat is rejected to atmosphere in the final stage. This approach leads to some very simple equations. All the combined fuel and air is considered as a single ideal gas. I have outlined this in the attached diagrams. We can discuss these further if you like.

Your picture is too small to read. When you repost it, please also say specifically what your question is, this is too general.

Great help there, wtf. +1

Please explain what this means?

Much work connecting (acoustic) science to music was carried out by the late victorians (Lord Rayleigh: The Theory of Sound is still the definitive classic text) and in the early part of the 20th century. The 20th century saw the study widened to include the mechanics of the human audio system, both physiological and psychological. Philips (Eindhoven) carried put much research in the 1940s to the 1960s and produced a marvellous book on the subject. Unfortunately I have lost my copy. There is much reported in the Blackie Student's Physics series, vol II, Acoustics by Wood. In modern times there have been a number of good texts, websites (some teaching) and so on devoted to this. You can even take degree courses in the subject at Cardiff and London Universities. https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=the+physics+of+music&gbv=2&oq=the+physics+of+music&gs_l=heirloom-hp.3..0l10.815.4290.0.4747.20.13.0.7.7.0.192.1518.3j10.13.0....0...1ac.1.34.heirloom-hp..0.20.1796.4U6t-WdYkY8 Go well in your search.

And how exactly do you 'run the probability' (ie what probability do you use) if the event has never happened? BTW this is a serious issue in statistics that has been argued for several centuries and is not yet properly resolved. 'Classical' statistics has no answer, you need to go to Bayes theorem.

Sticking to the statistical part of this question, How do you assign probabilities to something that has never happened?

Very much so. +1 The pdf is good.

The product is mechanical work. bcraig, Please fill in some background on for us - tell us where you are coming from in terms of Science. These are enormous questions to answer even with sufficient physics background. I seriously suggest you do not start with enthalpy and entropy, but work through your list in reverse order. Conduction, convection and radiation are much easier to understand and should be tackled first. I suspect you already have some understanding of this part. Doing this will have the advantage of building up your store of knowledge and success. Work from what you already know to what you want to learn, not the other way round. In particular do you understand 1) What energy is and in particular 'heat energy'? 2) My answer to your specific question (3) above about mechanical work? It is impossible to approach the rest of your question without this understanding. Finally you have duplicated your question. This makes for communication difficulties. Please keep it all in one place. But rest assured, plenty of help is available here.

Raider, thank you for the polite reply and being interested. It is a pleasure to help someone with this attitude. +1 Basically we are interested in some quantity or property, (for example volume, position, energy ) that depends upon other quantities or properties. (for example volume depends upon length x width x height). We call these other properties ‘dimensions’ or sometimes generalised ‘dimensions’. In popular parlance the word dimension refers particularly spatial dimensions as with the volume example. Generalised dimensions are more used in the energy where a body may have mechanical energy, thermal energy, electrical energy , magnetic energy, chemical energy and so on. Returning to the volume example, another term of importance is ‘The number of degrees of freedom.’ This is the number of ‘dimensions’ that can be independently varied. For a general volume that is 3 Considering the volume of baking tins that are 2 inches high, the height is fixed so there are only 2 degrees of freedom. The fixed height is known as a constraint. Sometimes the constraint comes in another form. For instance if we talk of the volume of baking tins with a perimeter of 40 inches if we know the length, we can calculate the width, so both cannot vary independently. Finally it has been discovered that some properties appear frequently and work has been done to find the minimum and best minimum list of ‘dimensions’ that we can use throughout Science. Since there are many possible candidates, international standards have settled on half a dozen on this list. There are Mass, Length, Time, Temperature, Electric Current, Illumination. They are given symbols M, L, T, [math]\theta [/math], I and C. Remember these can all vary (they are variables) so Physics constants (such as the speed of light) do not appear here. In our volume example Length appears three times and we write this as L3. No other dimension is needed. Kinetic Energy is given by one half mass times the speed squared. Now the constant half is not represented, and speed is distance divided by time which we write LT-1 So energy is M(LT-1)2 = ML2T-2 The interesting thing is that all forms of energy can be reduced to this. Does this help?

Dimensions? The word is almost completely meaningless without the rest of the sentence. Dimensions of what? There are no such things as the first, second, third, fourth or fifth etc dimensions by themselves.

Well you need to understand basic (without friction) forces and equilibrium (statics) before tackling hydrostatics. So where do we start? Do you know what a force is? Do you understand that if a body is static (not moving) it is in equilibrium?

I recommend you start with this part of the question. Ask yourself, Is the wood in equilibrium? If so what forces are acting? Draw a free body diagram. Does the wood actually loose weight?

Even in the computer world it is not possible to simultaneously update every cell. But I was asking the more fundamental question What does simultaneity (=sync) mean in this context?

This is a bit like Conway's 'life' automaton, ( https://en.wikipedia.org/wiki/Life-like_cellular_automaton ) with the composing and decomposing, however there is a major problem the the condition supplied "all in sync" What does that mean? Instantaneous action at a distance, extending throughout the universe? We know from relativity that doesn't fit with current observations on our universe. Another automaton Langton's Ant https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=langton%27s+ant&gbv=2&oq=langtons+a&gs_l=heirloom-hp.1.0.0i10j0l9.1907.6141.0.9313.10.10.0.0.0.0.188.1593.0j10.10.0....0...1ac.1.34.heirloom-hp..0.10.1593.ANoT3MvVVKs is more promising. The active agent (the Ant) propagates within a preset grid, and constraint squares can be randomly or regularly seeded.

First some general advice. This does not appear to me to be a homework question asking us to do your homework. You would likely find more answers in the appropriate secience sections as many members do not bother with the homework section. Now some facts. A collection of small crystals has a larger surface area than a few large crystals of the same mass. The larger the surface area the more energy the stuff has, due to increased surface energy. Since matter seeks the lowest available energy state large crystals are energetically preferred. This applies to all crystals, not just metallic ones. So given the opportunity, small crystals will join together to form larger ones. (I will return to this) However there is another mechanism at work. When crystals form, they start to grow from what are called nucleation sites. A nucleation site is a small zone in the cooling liquid that has dropped below melting temperature, or perhaps an impurity, or a concentration excess in a solution. Either way a solid crystal starts to form and grow from that site. The faster you cool the liquid, the more sites there are so greater numbers of smaller crystals form. That is why you need to grow crystals slowly to achieve large ones. Back to metal that has been solidified rapidly and therefore has small crystals. The grains may be viewed as lots of crystals with different orientations 'stuck' together to form the metal. As noted above, the smaller the crystals (grains) the larger their surface area so the seek to lower the energy by coalescing. Gentle heat and slow cooling injects just enough activation energy to permit this. Does this help?