studiot

OOps You seem to have contrdicted yourself within the first few lines. Two things for the universe so where did charge come from - That's three things or is it four by my counting.

You have asked a very good question, that is worthy of more than a few moments thought. Do you know the difference between intensive properties and extensive properties? Extensive properties are additive. They depend on the quantity of matter so each tiny element of the body contributes and they all add up. Examples are mass and volume. Both of these can be measured pretty accurately. Intensive properties, however, do not depend upon the quantity of matter. Examples are temperature, density and pressure. Normally we want one single value to represent the whole body concerned. By asking this we are effectively want the whole to be homogenous and isotropic. Chemists try to can achieve this by stirring for instance. When the body is not homogenous, ie the property varies from point to point within it we can indeed take an average, summed over the whole body (or part of it) An example would be the average surface temperature of the earth. Intensive properties are therefore, by nature likely to be less accurately availabale than extensive ones. Does this help?

The essence of Chaos mathematics is that it is non linear, so why would you expect linear algebra to be applicable? Since Linear maths is much much easier than non linear maths most disciplines try to use it for models and to 'linearize' whenever practicable. I am no expert in astro stuff but I expect they are no different. Incidentally, you have referred to chaos theory as another astro science, please elaborate as this is the first I have heard of this connection.

What's so difficult? This sketch is a very simple way for a self discharging siphon to work. I would have to know considerably more about the strata to work out anything better. I have shown pipe like voids, but is more likely to be be faults / fractures or other features since it is natural, although natural clay filled 'pipes' do occur. and the 'void' may be a pocket of pervious rock, rather than an actual chamber. Of course, the siphon may simply be formed from the local folding of a thin pervious layer, sandwiched between two impervious ones, that gets recharged when it rains, until there is enough water in it to drive the siphon over the top of the anticline, thus starting the siphon until the aquifer is drained. It may then issue forth as a spring on the other side of the anticline at a local fault. The water may be entering not directly but along the interface between to layers ot strata. There are just oodles of possibilities. go well

With regard to the blog, which led me here, I thoroughly enjoyed the thread on Bohemian Gravity. http://www.scienceforums.net/topic/78785-bohemian-gravity/?hl=%2Bbohemian+%2Bgravity However I don't see any essential difference between this piece of pure entertainment and any other non interactive presentation.

It's been much better today.

But you have a mechanical valve in the cistern. If that failed would ther not be overflow? Have you never seen the situation where the flush does not terminate but continues at the reduced rate of the inflow?

Have you looked at your toilet lately? Does it not also have the same extended low rate inflow plus intermittent high outflow characteristics?

Such a broad ranging question, it's difficult to answer or narrow down. Try reading Cats' Paws and Catapaults By Steven Vogel Penguin. It is a small book that compares how nature does things with how man's technology achieves results and examines what you need to know to understand the workings of the world and apply it to your own needs. From what you say you should have no trouble understanding it and it may inspire you to narrow down you interest to some specific area. The book is probably available very cheaply second hand.

Not quite. Most chemical reactions require the breaking of bonds, before new ones can be made (if there are new ones). But breaking of bonds alone is only the first part of the reaction. The second part may release energy. The terms exothermic and endothermic refer to the entire reaction. It is the net direction of heat energy that decides. So if more heat energy is evolved than needs to be input at the beginning the reaction is exothermic. Likewise if you need to put in more heat than you get back the reaction is endothermic. Pleae note that the terms refer to specifically to heat energy. Does this help?

Multidimensions have application when you come to advanced mechanics. You should look up "generalised co-ordinates" https://www.google.co.uk/#q=generalised+coordinates+in+mechanics I once wrote a paper entitled "The use of the fifth quadrant".

I agree with the answers in the first parts. Whilst the two boxes are moving together they act as a single object as far as the rope is concerned and the friction between them counts as an internal force, so your calculatuion does not show any frictional retarding force on the lower box. As soon as they start to slide past each other the upper box exerts a retarding force on the lower box. thus you need to calculate this and do a horizontal force balance to find the actual accelerating force on the lower box. Does this help?

If you really want to study what affects lift and drag, then get hold of a copy of Physical Fluid Dynamics D J Tritton Oxford University Press

ARC, you may find that this book of interest is obtainable from your university library. Geophysical Geodesy : The slow deformation of the Earth By K Lambeck Oxford University Press

Fluid mechanics is tough and then some. You will need some additional knowledge to work through from first principles to your end result. There are two types if differentials used in fluids. Differentials track the variation of something (some quantity, say H). We are interested in two possibilities. 1) What happens at a particular point in space, as the fluid streams past. This type of calculus leads to the familiar ordinary and partial diffs you are used to plus the vector operator del. 2) What happens to a particular particle of fluid as it moves along ie how it changes velocity, direction etc. This is known as "differentiation following the fluid" and is awarded the symbol D. Various relationships between D and d can be developed. Your route from velocity potential to your result requires several supporting equations or theorems. Continuity or the conservation of mass (fluid) An expression for external forces acting on the fluid (gravity and surface) This is done in the D form. These lead to Bernoulli's Theorem in vector form. This leads to a differential equation that can be solved and manipulated to yield the expressions you have posted. A PM (private message) with an Email address capable of receiving attachments will get you scans from a text I think will be accessible (with some work) if you wish. It is too much to reproduce here. Alternatively fluid maths is Bignose speciality, he may help, again try a PM.

Agreed, but not good. Does anyone think that the problems are driving (potential) members away? It must be pretty frustrating to ask what is an important question to oneself and find that, even if there has been an answer, you can't get to it. I have noticed many questions lately in homework (ie not crackpot) that the OP never seems to return to.

I just wish they'd leave my porridge alone.

Not quite sure what you are after. You seem to be proving your theorem by coordinate geometry, using a trigonometric paramaterisation. Are you sure you don't mean x= a cosh t and y = b sinh t ? (as opposed to cos and sin) It is also possible to prove this by classical geometry. Proposition: "The portion of any tangent to a hyperbola intercepted between the asymptotes is bisected at its point of contact." Let the tangent at any point P of a hyperbola cut the asymptotes in L and L'. Join P to the focus, s and draw SK parallel to one asynptote CL produced. Draw perpendiculars LM and L'M' to SP from L and L' Then the asymptote CL produced is a tangent, whose point of contact is at infinity. Therefore LS makes equal angles with PS and SK. Thus the perpendicular from L to SP is equal to the perpendicular from L to SK and therefore equal to the perpendicular t from S to CL produced and is equal to BC. Thus LM = BC = L'M' sinc ethe perpendiculars are equal LP = PL' It is also possible using an algebraic parametrisation. Here it is for a rectagular hyperbola ( the X and Y axes are then the asymptotes) xy = c2 : x = ct; y = ct-1 Tangent is y - ct-1 = -t-2(x-ct) When y = o ie at Q -ct-1 = -t-2(x-ct) c = xt-1 - c x = 2ct, which is twice the x coordinate of a point that also satisfies the hyperbola (x=ct) ie the point of contact or tangency ie the x coordinate of P When x = 0 ie the point R y-ct-1 = -t-2(0-ct) y = 2ct-1 so the y coordinate is also twice the y coordinate of the point of tangency, p, satisfying the parabola.

It's currently about as fast as the syrup on my porridge. I had time to make a pot of tea this morning between clicking on SF in favourites and seeing the opening page. This information may be helpful: It is consistently about ten times as fast between 7pm and 10 pm GMT as it is between 7 am and 10 am GMT in my UK location.

Please take note that the uncertainty principle does not only apply to quantum mechanics. There is an uncertainty principle inherent in the mathematics of classical wave theory. This is the simplest reference I can find. http://www.sciteclibrary.ru/eng/catalog/pages/11221.html

Well for calculating an individual sine a series method like yours is more efficient than a table, pretty obviously. However the OP seems somewhat confused since he has burned his log tables and jumped up and down on his calculator, but he has access to excel (pun intended). So he has at least two calculators available (excel and the windows calculator) Setting that aside and assuming we are going back to the days when we either had a four function adding machine or even only long had pencil and paper a table comes into its own when we want to calculate lots of values of the function, since much of the work is used over and over again. One constructed at say 15 degree intervals Newton's divided difference procedure will get as many values as you like. The first polynomial has one subtraction, one addition and one long multiplication. Since you build up each polynomial result by adding to the previous the fourth polynomial will get you sine values roughly equivalent to Chambers seven figure tables for four extra multiplications over the third polynomial.

Do you not have any ideas? What do you think the important variables are? What do you think might interfere with the test? What metals are on your list as having carbonate ores?

Exam on Monday? This is basic. Work = force x distance = pressure x volume Ask yourself what force or pressure would the work be done against if the above condition were met?

If you employed a lofting draftsman from boatyard I expect he'd be very very good at it.

Regretfully I have to disagree. This discussion has occured several times recently and each time a mathematical proponent have backed away from offering a mathematical solution or route to a mathematical solution to a part of physics that requires a physical process to take place in order to determine the result. I repeat that challenge here. I will tell you as exactly as you like how much coarse aggregate, fine aggregate and cement (or you can tell me it doesn't matter) and I ask for a mathematically exact quantity of water to add to make concrete of desired consistency and strength. There are methods which will get you near, but the final exact quantity has to be trimmed to suit as part of the process.