studiot

I note several research articles for analysis of the Donnan Equation with divalent ions, some using numerical methods to solve the equations. Presumabably you need to go back to first principles to derive the relationships.

Very good (teaching) points Sensei. +1

Since you have posted this in homework help I assume it is not a trick question from somewhere, but real coursework designed to make you think. Well done for detailing your thoughts, but you haven't actually stated the question as posed. So I am going to make some assumptions. what will the final temperature of the water be? The ice melts because heat is transferred from the water to the ice. So what are the conditions required for heat transfer to take place? Ans: There has to be a temperature difference between the water and the ice. Since the ice starts at 0oC (Assumption number 1 ) and the water starts at 10oC heat is transferred from the wate to the ice, which cools the water and melts the ice. The cooler water is now at a temperature lower than 10oC. You are told that the mass of ice is irrelevant but you are not told that the glass is insulated (Assumption number 2) Assumption number 3 is that the glass of water is initially in equilibrium with its surroundings. Since the water is now cooler than its surroundings heat is transferred from the surroundings to the water. So what do you now think is the final temeperature of the water ?

Hey, Mig be careful with my cup!

Then you need to be more specific. Are you defining 'natural' as inanimate or non human or what?

You didn't say but I assume the combustion takes place in an adequate supply of oxygen. You need to write balanced equations for the combustion of cocaine and sugar and combine the two equations into a single one, using the proportion of cocaine = X and the proportion of sugar = (1-X) Have you done this?

You keep claiming there are no 'natural' (ie totally independent of humans) processes that can lead to the formation of a (ceramic) cup. I proved this totally wrong in my post#22 where I demonstrated one such sequence.

You should research papers by the following geologists. Jean-Philippe Avouac (Cambridge) https://www.google.co.uk/search?q=jean-philippe+avouac+cambridge&hl=en-GB&biw=&bih=&gbv=2&oq=jean-philippe+avouac+&gs_l=heirloom-serp.1.0.0l3j0i22i30.3313.4032.0.6172.5.5.0.0.0.0.78.390.5.5.0....0...1ac.1.34.heirloom-serp..0.5.390.2xuuHcufdEM Philip England (Oxford) https://www.google.co.uk/search?q=philip+england+geology&hl=en-GB&biw=&bih=&gbv=2&oq=philip+england&gs_l=heirloom-serp.1.2.0l2j0i22i30l8.75704.80829.0.85641.14.13.0.1.1.0.265.1532.4j8j1.13.0....0...1ac.1.34.heirloom-serp..0.14.1563.HzMkO7zvC5s Who are (the) leading researchers in this field. The BBC produced a program about this with lots of computer simulations. Unfortunately I don't think it is availble in India, though it may be on youtube. Look for Earth Story (episode 4 I think) There is also a book and a DVD made by the BBC for this. The BBC material will be a little less technical than the boffins.

I have been unable to open yopur link on older systems and newer ones reject download of your the pdf as unsafe. However I can read it online and I see that it contains some glaring chronological errors. How can one eruption simultaneously wipe out the dinosaurs and bury ancient Indian civilisations? These events were separated over (edit 250 million) millions of years in time. You are however correct that there is much evidence that the fomation of the Himalaya and Tibetan Plateau is much more complicated than a simple collision between plates and that vulcanism from reheated rocks produced lava eruptions. Furhter the Tibetan Plateau appears to have originated as the ocean floor of the Tethys ocean and been uplifted. The current theory is that the mountain chain root was so deep it melted and separated downwards, allowing the upper mountain body to bob up.

Thanks for the advice and link, Endy. +1 The setting was indeed Quick access. However changing this did not properly cure it. For instance on the desktop there are 3 shortcuts, but it persistently only reports one of them.

Since my windows XP is getting increasingly difficult to use I thought I would try 10. Great for the first week then File explorer 'lost' several important folders I had recently created. Instead it concentrated on showing me all sorts of rubbish I didn't ask for and don't want. Surely the point of a file / folder listing program is to list files?

Are you sure? Look at the 'spectrum' of the low pressure sodium lamp here and compare with other lamps. http://www.lamptech.co.uk/Documents/SO%20Spectral.htm If you filter that line out you will have nothing left.

Sodium bulbs produce monochromatic light. (Do you understand this ?) Actually I think they have two very closely spaced lines.

I don't understand the question. Is this about money or modern ways to create filters? Before modern coatings on glass, filters were made by dissolving suitable absobers in gelatin and letting them set. This was much cheaper for amateurs. Perhaps you could reasearch this. What light do you want to filter out? https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=gel+filters&gbv=2&oq=gel+filters&gs_l=heirloom-hp.1.0.0l6j0i22i30l4.844.4032.0.12282.11.11.0.0.0.0.235.1502.0j10j1.11.0....0...1ac.1.34.heirloom-hp..0.11.1502.Rr4PoIZwVVc

Somewhat dificult to comment without knowing the %s involved.

Thanks a bundle Endy, I will investigate this further. +1 I note that the IP is listed along with some more. Others beware. The IP is a gateway and some ill intentioned users hide behind random letters as in my screenshot.

I don't have another browser.

Don't forget in the realm of thought experiments we are able to escape the chains of an imperfect universe. So all our equipment can be perfect. Further we do not need to specify how a given state could have been arrived at, so long as it satisfies the physical laws invoked.

Still hoping for an answer here from the site heirachy. If I block this IP in internet explorer I can't get to SF at all.

What is not clear is why you don't respond to my comments ?

This is incorrect. t is not squared in the formula final velocity = initial velocity + acceleration times time (V = U +ft) Be careful with your signs as well is g positive or negative? the correct expression for time to vertex is t =( v1sin(a))/2

If the hydrogen bond were covalent, which hydrogen orbitals would the electrons occupy? Is your diagram referring to something specialised like this? http://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/mirai-en/2011/4_11.html And how is this all related to the topic?

A discussion about the relationship between life and thermodynamics can be quite interesting unless only one side in that discussion is allowed to speak.

I am currently reading this fascinating book about the effect on sea levels the last time the icecaps melted about 15000 years ago. It was written by a Californian sailor and discusses now submerged places such as Doggerland in the North Sea and others around the globe in the light of the effect on human history as well as changing landforms and coastlines. Doggerland is interesting because the oil companies have released much North Sea survey data for study by anthropologists, and other scientists. No outlandish claims are made and the book has lots of solid references to modern research results. Below is an extracted map of Doggerland. The main point seems to be that sea levels rose rapidly at the end of the last ice age, but that rate of rise has been slowing down since so most of the 120 metre rise occurred in the first 9,000 years and modern day coastlines appeared 6,000 - 5,000 years ago. Geologically this is really a very short time, but nearly all human development has taken place in this time. Edit, nearly forgot to reference the book The Attacking Ocean Brian Fagan

This is a good example of how a practical physicists can have a feel for the question and use physics to 'prove' the maths rather than the more usual way round. So consider the line L (forget the directrix) as the position of a plane wavefront. By definition of a wavefront the light arrives/leaves at all points along a wavefront at the same time. We know from physical observations that a parabolic reflector brings parallel rays to a common focus F. So this can only happen if rays leaving any point Q on the wavefront L travel the same distance to reach the focus, since they all leave at the same time and travel at the same speed. Note that the line L does not have to be parallel to the x axis as you have drawn it. As a practical chap yourself you might like to read Mark Levi's book The Mathematical Mechanic. Mark sets out to prove many common mathematical theorems using the laws of physics "Using Physical Reasoning to solve problems"