studiot

Look carefully AD is the y axis or the line x = 0. AB is the line y = 2 DB is the line y = 1/2X2 I said this was the area of interest, ie the plate.

The clue is in the word 'draw'. I assume you understand what the tangent and slope iare. Sso when you have a measured curve and manually draw a tangent to it at some point the tangent will be a straightr line with the same slope all the way along it as far as you care to extend it. To calculate that slope you can either use a protractor or most people do it by taking two measurements with a ruler - The Y coordinate change and the X coordinate change, and then dividing one by the other. Clearly the larger each of these is the less % error your measurements will make. So the phrase is conveniently large, that you can measure with your ruler. Does this help?

A learning point here. Your analysis route was quite complicated. When they teach series and parallel circuits, using resistors the fact that in a series circuit the same current flows in all series elementrs is highlighted. Capacitors do not have conductive current, but capacitors in series have the same charge. This is often overlooked. But it can be used to develop simple and useful relationships.

For 70 attached is a plan of action. The area of interes forms a curved triangle which I have labelled ABD. The centroid of ABD is labelled T which has an x coordinate [math]{\overline X _T}[/math] The area under the graph of [math]y = \frac{{{x^2}}}{2}[/math] forms another curved troangle I have labelled DBC. This has centroid V with x coordinate Note that these two curved triangles fit together to form a 2 x 2 square (I have labelled this ABCD) This square has centroid S with standard values for its centroidal position. Now the trick is to realise that the moment of this square must equal the sum of the moments of its two componeent curved triangles. This should be a good start for you. As to question 69, Are you sure you have presented the problem correctly? The half metre length of string must go slack at the intial throw and only become tensioned when the mass has fallen back. The questions states that theta is measured to the left, ie when the mass is hanging on 1.5 m of string and swings to the left, clear of the peg. This would make the radius of circular swing 1.5 m.

Ok I have read through your working and here are my thoughts. 1) It is nice and - a pleasure to read, unlike some. 2) You have correctly deduced that for dielectrics havinf the same cross sectional area in series the electric field strengths (or potential gradients) are inversely proportional to their relative permittivities. Well done. 3) You have correctly used this to establish that the air layer will be the first to breakdown and subsequent working is correct to calculate that voltage. However 2) You need to be carful with terminology: permeability refers to magentic effects. The correct electric term is permittivity. 3) Apart from the silly sign in the power of 10 I agree with your arithmetic so far as it goes and you have found the sign error yourself. 4) But the question was What is the maximum voltage that can be impressed and you have not addressed what would happen after breakdown of the air. Would the capacitor fail? In fact I suggest that the air layer would fail (ie become ionised and of low resistance) and the capacitor would continue to function with only the porcelain dielectric acting. Thus you can recalculate the voltage where the porcelain would fail by considering the air a short circuit. Does this give the answer they seek?

I have just put my thought down in this thread both about the orientation and size of posted pictures. Neither too large nor to small and the correct way up. greyscale also saves space. Could some instructions along these line be drafted so that we could point to them?

This is a more suitable size of file 300k instead of 3000k. Greyscale also helps if you don't need the colout. And please put it up the right way. I have just spent the time I could have been reading it doing this for you. I will be back later when I have read it.

You are more polite than I am. +1

Perhaps you should post in the poetry section ? We could then get the resident poetry specialist to dechipher it. Let us start with this one. Looking back I have to say that I made a mistake because you specified a positron and I wrote about a proton. My apologies. So I now see why you keep asking about "in an atom". An isolation box is not an atom. Of course there are no positrons in an atom. An isolation box is just a theoretical way or device for including one positive and one negative charge to say that the net charge is zero. When I asked you to state the Law of conservation of charge I wanted you to understand that the Law does not say simply charge is conserved. That is not good enough. The Law also includes a description of the place where the charge is conserved - the isolation box. Otherwise you could simply say that charge in one place (or within one 'box') is not conserved because the charge moves outside the box or because you include a charge that was somewhere else when the process took place. So when we talk about the conservation charge for an electron - positron annihilation on Earth we start (before the annihilation) with one electron and on positron - net charge zero - in the box (Earth) After the annihilation we must still keep the same box (Earth) We cannot suddenly include a positron on the Sun. Since we now have no charges in our box the net charge is still zero. If we had one electron, one positron and one proton (to start) then the net charge would be +1+1-1 = +1 After the annihilation the net charge would be 0+1 = +1 Again charge would be preserved. Remember also that there is no requirement for the charges listed to be connected in any aprticular atom or even to remain in that atom or molecule if they are. The Law is not about atoms. For instance consider the ionisation of common salt - sodium chloride. Yo start off with one neutral molecule of sodium chloride. The net charge is zero. Following ionisation you have two ions one positive sodium ion and one negative chloride ion. The net charge is still zero. If this is this any better we can move on to 'mass charge' and 'shadow stuff'.

O great God Moderator I pray to you to save us from the evil of this thread and close it.

How does this meet the Uncertainty Principle?

If you are going to do any sort of degree you are going to need to do some degree level thinking. So I suggest you get your thinking cap on and re-read what I said about the common core.

Hi, It's good to think seriously about the future. Here are a few things you need to know. Most colleges/universities that teach engineering degrees have a 'common core' for the first year for mechanical, aeronautical, automotive, production, civil, building services and so on. One bonus of this is that it is easy to switch after the first year if you decide to change the emphasis of your studies, when you specialise. The studies will include the basics of mechanical science, materials science, electrical science, engineering mathematics, engineering computing and so on. The computing element will be about the use of computers. Specialist computing courses will be about the design of the software that engineers (and others) use, and/or the design of the computers themselves. It is not usual to get several first degrees (Batchelors) for several reasons. The usual route is first degree then a higher degree - a Masters (which may be in accounting or business and taken after a few years industrial experience) Remember much of the art of engineering is about best use of money. The other reason is that full/top professional qualifications for most engineering disciplines used to be available at Batchelor degree level, but have now been elevated to require Masters. Does this help? Please ask if you have further questions.

Was your crash the file explorer crash mentioned in your link, because that crash has nothing to do with any router. Can you describe your problem more fully?

And just how many bodies does it take to supply an electric current? So you need one body to supply rhe current in the first palce, the superconducting coil and another body to take the energy out again. That's three bodies. And that's not counting all the charge carriers as bodies.

Well I'm sorry you don't consider my answers 'satisfactory' I am pretty sure this is due to a language difficulty. I am guessing here, but can you tell us why Pretty well every time someone offers you an explanation you come back with new expressions that are not scientific English. I try to keep the English simple to avoid this but Mass charge ? To me this is the weight of gunpowder you put in a cannon or musket. Shadow Surely a photon is a quantum particle of light. Even in normal ordinary English a shadow is the absence of light. And what does the statement that an electron possess an electric charge and two electric charges mean? To me that adds up to three charges. Can you not get some help with your English ? This would be much less painful.

Indeed, it's called finite element analysis if done formally and can be a very powerful calculation technique.

Yeah, I'm not contesting your offering because you must be as much in the dark about what PrimalMinister's ill formed phrase means as I am. But I am certain that whatever it means, replicating it 64 times cannot possible produce a valid chessboard. As a matter of interest using the chessboard to explain probability, leading to an explanation of entropy is a good solid explanation; there are many spurious explanations about.

@DannyTR And please reply to the question I asked you about 35 posts back in the middle of page3. None of the succeeding posts have addressed this question. I also explained in that post why I had broken my discussion down into small pieces and Why you were totally wrong to introduce the 'number line' as an explanation of your contention.

It's more than this. 1) If all possible combinations is a list of all the pieces that could be on a 'template' square, Not all squares have the same template. For instance there are 8 squares that cannot be accessed a black pawn and 56 that can. 2) Some of the posiibilities are contingent upon what is upon the other squares. For instance there is only one white king. So his presence on any square is contingent upon his not being upon any other. 3) Finally, there are only 64 squares on a chessboard. So if you take a template square and repeat it 64 times you will have 65 squares. Scientists pay attention to detail!

I asked you a simple straightforward question. Are you still refusing to answer?

This can't possibly be right, unless you are misusing the phrase all possible combinations. So please explain exactly what you mean by this.

I expect some Spartans cried when they left (some of their) children to die on the mountainside. Furthermore we have documented evidence of this practice. Recently a doctor had to climb up to a gantry on the Severn Bridge, to cut off a trapped worker's arm that could be freed, just so that the rest of him could be saved. Was that doctor evil or his heart clouded or what?

Well I think the Lone Ranger (AKA Swans) got on top of it pretty smartly when he arrived. What worries me is that there were several new starters around the time with unusual and a bit controversial posts, some a bit similar to the troll's provocations. And I wondered it he had slipped in another puppet amongst them for later use? He must have realised the eventual outcome of his unacceptable actions. Subsequent to the original bans I also saw both the original account and subsequent puppets listed simultaneously in the members list as online on several occasions.

Then Google is even thicker than I thought. The point is that I tried it several times, logging off and logging on again and each time I came back to this thread I got this. And the advert didn't 'rotate' - it remained fixed. Perhaps it was one of those things. Today I am being bombarded with rotating financial ads.