studiot

Thanks for the additional info cnewton.

Hello gwiyomi Well it is the reaction between two molecules can you name either or both, Because the name of one should give you a big clue as to what sort of reation it is. I think also that there needs to be a lot more of one of the reactants than is written on your board.

Yes that's correct. Number of moles = Mass / molar mass Molar mass = Sum of the individual atomic masses taking account of numbers of atoms Mass concentration = total mass of substance per litre = total mass/ litres Molar concentration = number of moles per litre = number of moles / litres Have you studied balancing chemical equations yet? I'm doing a chemical preparation at the moment (cooking the dinner) so I will keep going away and coming back. So keep watch, others may also offer help meanwhile.

Well your experiment was more complete than the ones I linked. Did you take the measurements youreselves or were they given to you? First we need to settle the chemical formulae. Can you write down the formulae for ammonium chloride, sodium chloride and water? Can you then calculate the molar masses?

Was your coursework anything like these? http://www.scienceforums.net/topic/85620-chemistry-coursework-2014/ http://www.scienceforums.net/topic/85585-gcse-coursework-2014/

I think there is a considerable difference between the tone of post#98 and post#101, although both argue against Michael's points. Thank you, sunshaker for your observations, perhaps some whow ahve attended formal schools should note the motto of this ancinet school, Peter Symonds School, Winchester 'Manners Maketh Man'

This doesn't only affect baseball, it applies to all bat and ball sports. I can think of at least four reasons, others may add more. Two affect the quality of the strike and two affect the batsman. The first reason is that it is easier and more reliable to carry through a smooth path that does not end at the ball, ie it starts with the backswing point and carries on towards a point beyond the strike point. This path should be such that the bat is travelling at the best speed and in the most appropriate direction for the strike. The second reason is that attempts to change this path can result in 'jerky' action that diverts energy away from the optimum hit. The batsman may even attempt to pull up too soon thereby reducing the power of the strike. Note that some bat ball sports require wrist action as well as arm action. Timing of this is easier with a full swing. In some sports the batsman needs to immediately (rapidly) recover his 'ready' position. You will find that the follow through includes an optimum path to this. Finally the batsman doesn't want to hurt himself. Checking a travelling weight will result in reactions within his body, and contiually doing this may cause injury.

Post#96 That's an interesting and insightful post, Michael. I wondered where you were going and had some sympathy with your some of your earlier comments. Unfortunately hackles do sometimes rise, particularly about certain subjects, a bit quickly here. Although this forum seems better than most, due in good measure to relaxed moderation. @elfmotat I asked a similar question some while back but drew nowhere near the size of discussion we are heading towards 100 posts and still going strong. Take courage from that.

Why wait till Monday? I published one in June 1986, just for you in "The Survey Review", although I liked the rag better when it was "The Empire Survey Review". My article was entitled "The Use of the Fifth Quadrant" Well I don't have a PhD, though I do sport other postgrad qualifications that I don't bandy about, and I have been know to help modern PhD students with their studies. My feelings on the PhDs and Msc is that the qualifications have become devalued in recent years with the plethora of mediocre takers we now see and I cringe at some of the things that they are awarded for. After all that is what Albert got for Relativity. You are nearer the truth than you think. In 3D differential geometry one of the first things to recognise is that a line can twist or curve in two perpendicular directions at the same time, or not as the case may be. So it may be straight in one of these directions and curved in the other! Never mind the clever stuff, the animation showing this is good http://en.wikipedia.org/wiki/Frenet%E2%80%93Serret_formulas

I like this simple way to put it. I hope those red blooded physicists note that no maths was needed and no mathematicians were harmed in the production of this post. +1

9.6% I wish my bank gave me that much interest!

elfmotat is pampering you - I was going to ask for a diagram. This statement probably needs further explanation. We are approximating arc PQ to the perpendicular from P tp OC. The smaller alpha is the more nearly exact this is. Which brings me to the sort of conditions we are talking about. We assume all rays meet the curved surface near the axis OC. That is alpha small. Such rays are called paraxial rays. These conditions are typical of eyes. We are also approximating the curved surface by a circle. This is true in spherical lenses and paraxial rays, but not true in tall thin lenses. CP is a normal because it represents the radius of curvature at P and is therefore perpendicular to the tangent at P.

Perhaps you should tell Mark that? The table appears in 'Mark's Handbook for Mechancical Engineers ' as table 3.2.4 though I would have thought by the tenth edition someone would have already pointed that out if it were untrue Mark's is, of course. the 'CPC Handbook' reference for this field. There are some interesting notes and other tables, however, since conditions such as the presence of surface films make a big difference. Table 3.3.3 lists Friction for Steel on Steel dry 0.78 Oxide film 0.27 Sulphide film 0.39 Friction for Copper on Copper dry 1.21 Oxide film 0.76 Sulphide film 0.74 Engineers should learn to read the correct table correctly. You may have been thinking of the data from the oxide tables. Mark gives further data for specially ground harder steels that reduce these values even further.

Isn't that like the detective asking the suspect to admit to murder, why would he? and why would anyone admit to promoting a theory that "does not stand up to scrutiny" Pope was not the only poet quoted here. Coleridge was also an accomplished mathematician and wrote a very famous letter to his brother about it.

Yup that's it. This one was really too easy, compared to the last one.

What happened to the overheads?

No need to be sorry. Ratio and proportion puzzles many people, but we got there in the end and you did most of the work yourself. I'm glad to help anyone prepared to put the effort in.

My post#6 was meant to stimulate questions about your integration. I don't see a logarithm creeping into your working and there should be. What is the integral of a constant times dx and what is the integral of dx/x ? Note I haven't cheched you separation of variables to see if you got the original fraction correct, fuzzwood already asked you for that and I don't see that either.

Well I was considering reporting the downright rudeness of 1) Not replying to my questions (which were about your request) 2) Posting deliberate nonsense ("Doesn't mean anything sir") I seem to have wasted my time and effort on your behalf.

Thank you for the link, I will give it a try $\int \frac{a+bx}{cx}dx=\int \frac{a}{cx}dx + \int \frac{bx}{cx}dx$ Yes it works in one hit and the code seems simpler than MathType produces. So perhaps that (expensive) program will turn out to be a waste of money. +1

Well I don't know the difference between these options To post the three integrals I had to split the equation in three parts and post the LHS, the left integral on the RHS and the right integral on the RHS separately. If have no idea wht the system 'renders' the latex to. Each segment of latex code was produced in MathType and pasted as MathML. When the first attempt including all three integrals in one go did not work (in the simple reply box) I first went to the more reply options to see the preview and played with it until I beat it into submission, I first split it into two segments, RHS and LHS of the equals sign, which was written in ordinary text. When the LHS displayed, but not the RHS I split the RHS either side of the plus. That time it worked.

I would be very happy to learn more, though I suggest you hive this off to another thread, with a link left in this one, since it can be a real struggle to post a simple bit of maths like the above examples.

Thanks, imatfaal. I see the faint background now you mention it. To the OP, it is counterproductive to post insufficient information/description, if you are serious about it. All you achieve (as here) is a group of other baffled posters asking what you mean, instead of being able to get on with the discussion. Useful information would be what is the (approximate) date of the picture and where is it to be found? What material is is painted? inscribed? on?

That's jolly spiffing for those who speak fluent latex. Lingually challenged members like myself copy and paste from a formula editor. I find however that the renderer (is that the right word) can't chew even moderately complicated formulae so it is necessary to paste in sections either side of a normal equals or + or similar sign. For instance this would not take in one go but pasted OK in three sectrions, all enclosed in math tags as already advised. = +

Maybe I'm thick, but I have no idea what you mean.