studiot

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?

The net force causing the acceleration is Force = mass x acceleration. In the dynamics of motion we regard gravity as an acceleration (g), not a force, so Weight is the name we give to the force that gravity exterts on a body of mass m. W = mg In this system, remember that kg are units of mass, not force or weight. Force is in Newtons. (you have to convert if it is given in any other units) So W is in Newtons, mass is in kg and acceleration is in metres per second2 Does this help?

You are right to say there is more than one way to skin a cat, or more than one way to discuss this. However please be careful not to mix up ideas from different ways. The classic second law of Kelvin and Clausius refers to cyclic processes. This is not a cyclic process. You rightly mention that Chemists introduced the Gibbs Free Energy and chemistry/chemical engineering topics are normally discussed from this viewpoint. The free energy approach incorporates all forms of energy, heat, work, the entropy-temperature integral etc. Order is not expressly distinguished, it is included in the calculations. If you wish to discuss in statistcal mechanics terms (order and disorder) Caratheodory's formulation is better. https://en.wikipedia.org/wiki/Second_law_of_thermodynamics It is easy to state (it is obvious) that a crystal lattice is more 'ordered' than the solute phase. Unfortunately most people misunderstand this, so perhaps you would expand on this ??

endy, +1 for tenacity

The Ancient Greeks didn't do much 3D geometry but this particular result was due to Archimedes, though his approach and proof was rather different. The area is the same on an equivalent cylinder. Pity you didn't put that working into a spoiler, but well done for working it out.

When you guys have fully conquered 2D how about tackling 3D? Same problem but on a sphere not a circle. If you paint parallel stripes on a football so that in fiveworlds' post#4 each of A, B C etc represent a painted stripe on the football. How do you relate the area of paint to width / height of the stripes ?

Hammers are good for you. source: http://www.marksdailyapple.com/sledgehammer-workout/#axzz41YXPIOaX

Have you considered that there are other forms of rudeness besides direct insults, some of which are particularly counterproductive? Do you not consider it rude to post a question you clearly desire the answer to; for someone else to put possibly considerable time and effort into constructing a cogent reply, for the originator never to return. I post here to help others but I sometimes wonder if it is worth ever helping anyone again.

+1

The pictures are very pretty, can we see your attempt at the problem?

So am I. How can an acceleration equal (the negative of) a velocity? Please check the wording.

Here are some facts, figures and terminology. Source: Strahler, The Earth Sciences Meteoriods are tiny particles ravelling through space at high velocity. When they enter the Earth's atmosphere they become meteors. These are characterised by their luminous trails in the sky. They range in mass from .000001 to .001 kg and enter tha atmosphere at 25 to 80 km / second Nearly all burn up to gas in the upper atmosphere, 90 to 200 km above the surface. Because they are so small and so high, their destruction is accompanied by their luminous trails (50 to 100 km in length) , but no sound. Larger particles can make it all the way to the surface. These are called meteorites. These are accompanied by brilliant light and explosive sounds, especially upon impact. @Pavel another book you might find interesting http://www.amazon.co.uk/Atmosphere-Ocean-Our-Fluid-Environments/dp/0851412955

I respectfully suggest you check up on some basic classical mechanics before messing with relativity. It is a physical impossibility to hit something (ball) that is travelling faster than you (bat) are in the direction of its motion. This applies in ordinary Newtonian mechanics, just a much. Of course you can hit the object by striking across its line of motion, but that cannot impart additonal motion in its direction of motion.