Joatmon

In practice you always need to use a series resistor or some sort of current limiting circuit for a LED. It will almost certainly be destroyed if you don't. Very often when you buy a LED you don't realise that it incorporates a resistor ( especially so if given recommended voltage to use such as 6v). however you can buy a LED without a resistor. http://led.linear1.o...or-with-an-led/

If the wood is still a part of the original tree (e.g. a ceiling beam) it can often be dated by examination of rings in the wood which may be visible at the cut end of (say) a beam. This is known as dendrochronology. http://en.wikipedia....endrochronology Later edit : Sorry John C just seen #6

This is probably a "red herring", but patterns can be set up that "travel" at any speed you like - even instantaneously. For example a pattern travels down a waveguide faster than the speed of light. It cannot carry information as it has no real substance. Phase velocity Phase velocity is an almost useless piece of information you'll find in waveguide mathematics; here you multiply frequency times guide wavelength, and come up with a number that exceeds the speed of light! By the same argument consider a long pair of scissors. As you close the blades you will see the point of intersection travel along the blades faster than the speed the handles are pulled together. Now, consider a pair of scissors so designed that the two blades come together at the same time for their whole length. Could you not say the point of intersection travels instantaneously from one end to the other? http://www.microwaves101.com/encyclopedia/waveguidemath.cfm

Just a thought - do you think that the people with less than average intelligence are going to let this happen. If they think they, or their offspring, are likely to be selected they may physically band together and rebel - even those slightly above average (whatever that may mean) to be on the safe side. Desperate people feeling they may be denied reproduction rights may make better, braver, fighting rebels. In a civil war they may come out on top and in the process kill many of the "intelligent enemy". In a rough situation where civilisation is falling apart they may be more suited to survive, more capable of living off the land. (be more fit for survival in this situation).

Agree about the Johnny Horton video. If you can find a version in which the British win that would be rather nice (Oh I forgot for a moment it's history)

Thanks - relieved waking up the rather old grey matter didn't lead to a cock-up!

I don't why I'm putting this on - I'm British! Ah well, it's only history.

Perhaps the British should celebrate June 10th. It's our nearest equivalent to "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness." King John probably didn't see it that way in 1215, but it was a step in the right direction. http://www.middle-ag...magna-carta.htm

This is why I wondered about my interpretation of the formula - The 6 being the same size as the 3 left me in doubt about whether I was dealing with a root or a multiplication. Thanks for clearing that up. Later edit: did a bit of scraping away the rust and I think the formula given in #1 is incorrect. It seems to me that it should have been (6*6*6*(3^0.5))/4.

I have a couple of problems. I'm not too sure what you are trying to prove. Also, if I were asked to calculate the area of a regular hexagon I think I would do it differently to the way you seem to have been taught. Anyway let's see if I can help a bit. If I understand the formula you give and work it out I get approx 187. I make the answer you give approx 93.5 (which is half what I got for the formula). Assuming I understand the formula, one of these must be wrong. As you probably know your hexagon fits neatly into a circle of radius 6 so it's area will be a bit less than such a circle. I make the area of such a circle approx 113.1 which rules out the formula you have been given and points you toward the answer given.(assuming I understand the formula). In your formula it looks to me as if one of the 6's should be a 3 - alternatively perhaps the 2 should be a 4. Now how would I solve the problem myself? As pointed out by Swansont your hexagon can be divided into 6 equilateral triangles. I make the height of any one of the triangles Approx 5.196 I therefore make the area of any one of the triangles Approx 15.588 And so I make the area of the whole hexagon Approx 93.5. (Which agrees with the answer given) Note: I used Pythagoras to calculate triangle height. This may be where your method differs from mine? Because this is homework I have not shown any formulae used. Also because I'm quite rusty I would appreciate it if anyone else spots a mistake

You have 6 equilateral triangles. I expect you know the formula for the area of any triangle. I expect you can calculate the height of each equilateral triangle. Perhaps you have been given some incorrect information? edit - its UK bedtime now, but hope this is some help.

Just playing with the term "large body". I know - I've got a strange sense of humour. Dead loss really.

You have a formula and you have an answer. If the formula produces a different value to the answer then either the formula or the answer is wrong. If you have been given one of them then surely the other must be wrong. Are you trying to derive a formula or were you given both pieces of information?

There is a large body of opinion that says it should be.

I know this is really "off topic"but I can't resist posting. I am so pleased to be able to take the attached photo. I know it's a terrible photo - cheapest Fujifilm camera you can buy, taken through glass in the dusk of the evening with the flash disabled. BUT it's my front garden and we have a pair of UK robins feeding young in an overgrown Acacia hedge that really needs trimming - I have a marvellous excuse to put that job off for a while!

I think Shakespeare was considering the kind of love that lasts a lifetime. In a long term relationship such as marriage there will be rough times of difficulty which a poet might describe as tempests. Perhaps "to the edge of doom" is a poetic way of saying "unto death". Looked at that way I find the sonnet very touching.

With reference to #1. I hesitate to join in as I'm not mathematically inclined and haven't done more than glance through the thread. However, it seems to me that a very basic principle may not have been taken into account. F=BIL. Perhaps it's because the vectors haven't been drawn to scale, but length of the conductor segments doesn't seem to have been taken into account. Obviously current and orientation in space of every point has to be taken into account. If you think of dividing the coil into many equal length pieces and draw a force vector for each piece at right angles to that piece IMO they should add to zero. If this point has been covered then please accept my apologies.

I wait for the great revelation. I would like to know if I got it right over half a century ago. This song illustrates how things happened for my wife and I. http://www.youtube.com/watch?v=l_9jTjsowwc

Well Moontanman, if we are going to lower the tone..............

Nobody seems to be considering the feelings or traumatic effect actually ending life might have on the person expected to either provide the means or administer the procedure. The thought of this being part of a doctor's routine range of treatments might not be accepted by many doctor's for a variety of reasons.(Including, dare I say it on a science forum, religious scruples).

or, if you like, if (x^3)^2=(x^2)^3 (as already shown by timo) then x^6=X^6. Therefore any whole number (X) to the power of 6 has a whole number square root (X^3) and a whole number cube root (X^2).

Think about this for a moment - Venus and the Earth are approximately the same size. Then compare the size of Venus with the size of the sun (Actually Venus is smaller than it looks because it is a lot nearer us than the sun). Then consider that the sun is quite an ordinary star among millions of stars in our galaxy. Then think about the number of galaxies that are known to exist. Then try to guess how many galaxies exist without our knowledge. Then think that it is possible that all intelligent life in the universe may exist on a "dot" the size you see. Think of your place on that "dot". Think of how fragile the whole existence of intelligent life in the universe may be, let alone your own existence. I find this train of thought quite interesting, perhaps even frightening.

I see you reside in Uranus so its not your turn More seriously, I hope you are lucky with the weather. You wont get another chance for 105 years (or so I read). I'm sure you must have thought about it - but have a camera handy.

One thing I have noticed is that if I look around and someone is looking at me the natural reaction is for both people to look at each others eyes. The person doing the looking looks at your eyes to detect whether their action has been noticed and as you scan a room of people you automatically scan the eyes of other people around you. I think it may be an automatic reflex to judge people's intentions towards you. If you lock eyes, even for an instant, you are very aware of it (which can be embarrassing). I think when this happens it is easy to imagine you felt them looking at you before you looked around.

Actually the bird community are too busy developing miniature heat seeking missiles to attach to their wings. They are presently seeking advice on lightweight heat shields. These weapons are being developed by the hawks, but the doves are opposing this in favour of negotiation. http://www.answers.com/topic/doves-and-hawks