TonyMcC

The first thing to realise is that long after the switch is closed the current through the capacitors will cease to flow( they will have accepted all the charge they can). This means that after that time you can ignore the capacitors when you calculate the voltages across the resistors. When you look at it this way, the resistors are in series and the formula used is correct. This is the standard voltage divider formula. http://en.wikipedia.org/wiki/Voltage_divider

It might help to look at the circuit like this:-

The question concerns the following actions. First you charge C1 to 12V using the battery. By moving the switch to position B you disconnect the battery and use the charged capacitor to put charge into capacitors C2 and C3. At this stage you can ignore the 12V battery. Just considering the capacitors, you have a network that can be described as C1 in parallel with C2 and C3 which are in series. So how much charge does C1 accept when the switch is in position A? How does that charge get shared by the 3 capacitors when the switch is moved to position B?

On reflection, calling this a "goofy idea" is IMO rather unfair. It must have been from ideas like this that the German coding machine Enigma was developed. This machine was producing coded messages during WWII that were almost undecipherable. The hint definitely gave it away - so much so that I probably would not have produced the answer without it.

I think it is related to a "goofy idea" - hence my answer of 15. If I am correct, think "puzzle" not "math".

15

It reads as if the OP is asking if someone with a damaged brain might be given someone else's brain. This would be rather pointless (IMO) because you would, in effect, become the donor of the brain. If you were given a brain somehow artificially produced it would surely "be empty" and you would have to be taught everything again and I also wonder if the artificially produced brain would even have the instinctive responses needed for survival. I am thinking of breathing etc. On the other hand I am in my 70's so if anyone wants to put my brain into a young man's body when my time comes I'll give it a go!

You may be surprised to know that when a Russian MIG plane defected to the West in 1976 and was examined it was found to use old fashioned thermionic valve (tube) technology. There was some debate at the time concerning this. Was Russian technology well behind our technology or was this choice made as it was less likely to be affected by an EM pulse ? http://www.wvi.com/~sr71webmaster/mig25.html

Sometimes it takes an accident to highlight a weakness that in retrospect seems obvious. I remember reading about a serious air crash near my home in 1957. This was caused by a non-return valve being fitted the wrong way round. I understand that such valves now have different sized fittings each end to make it impossible to fit them the wrong way round. http://en.wikipedia.org/wiki/Sutton_Wick_air_crash

If you are asking if the voltage across each of a number of resistances connected in parallel is the same then the answer is yes.

As per this newspaper report:- http://www.thesun.co.uk/sol/homepage/news/3359016/Gay-guesthouse-ban-pairs-3600.html

Nobody seems in a hurry to answer this so I will give as my opinion that proof is extremely difficult and declare that it is beyond me. However evidence that it "works" can be provided by scale drawing over a few of the necessary (in the case of the square wave infinite) number of harmonics added to a fundamental frequency. It's quite likely that you have done this and are looking for more depth - if so then sorry!

I don't suppose this helps at all, but I always liked (and did quite well) in physics, but found the more serious aspects of mathematics less to my liking and did much less well in that subject. However, for some reason, I have always found geometry fascinating - perhaps because often the whole picture lies before you and can be considered rather like a machine.

It's homework - but I think its OK to point you to this web page :- http://en.wikipedia.org/wiki/Significant_figures

If a large crowd of individuals, many of them masked and hooded, gathered outside Hal's home, threw bricks through the windows and rampaged through his home stealing anything they could get hold of would he describe them as simply light fingered? Would he have any difficulty in deciding if they were "right or wrong"?

Can I inject a word of warning? Grapefruit juice can interfere with many drugs and people prescribed those drugs are advised not to drink it. I am one of those people. http://en.wikipedia.org/wiki/Grapefruit_drug_interactions#Affected_drugs

Wisdom, if it arrives at all, comes after many years of experience. There is scientific evidence that the old person who you think of as "slow" may be made wise by the very factors that render him/her slow and deliberate in their actions. http://www.dailymail.co.uk/sciencetech/article-1289300/With-age-really-DOES-come-wisdom-say-scientists.html

I wonder if something like the experience I described in another post indicates that there may be an element of truth in what Khaled says in post #6.(in NLP (Neural Language Programming), there is a complex techniques to experience slow realization of time-flow for short amount of time,) An interesting thing to me is how you might respond to increased speed of brain and muscle activity under critical conditions. Can you become a sort of superman for a short period if your brain decides that is necessary to conserve your life. It happened to me when I had to land a glider in a narrow field and collided with power cables (which are just about invisible from the air). The whole world seemed to go into slow motion for me. I had plenty of time to realise what was happening in the next, what must have been a very few, seconds. I changed my mind at least twice as immediately after realising what I had hit I let go of the controls and lifted my feet clear of the rudder bar. As the glider started to dip and slew I worked out that being in the air was my best bet and that electrocution was unlikely, so I got back on the controls, the glider responded. I levelled the glider about 3 feet above the ground, looked left and right to see if a snapped cable was coming with me and it wasn't so I made a normal landing. As I say everything described seemed to take ages. Obviously the world did not go into slow motion so my brain activity and physical movements must have working overtime!

I don't see you making any logical argument that my thoughts are not sensible and as I have harboured those thoughts for more than 50 years they can hardly be described as "kneejerk". If a child repeatedly demands more from a parent than the parent can afford it is being unrealistic. If the parent decides to use credit repeatedly to meet this demand then the parent will eventually be in financial difficulty. If employees repeatedly demand of their employer more than the business can support they are being unrealistic. If the management of the business decide to repeatedly use credit to meet these demands the business will eventually fold. If the citizens of a country repeatedly demand more than taxes can provide they are being unrealistic. If the government(s) of that country tries to keep in office by meeting the demands by steadily increasing the national debt year by year then even the government will find itself in financial difficulty. It seems, from today's news that there are many in the world, particularly from China, who share my concerns. I attach a quotation made by Charles Dickens in a novel written in 1849 that is generally accepted as good advice. I also attach a couple of "Hoover" quotes. I deduce that, like me, he was in favour of sensible levels of credit.

Obviously there is much truth in what you say and I did say I might be biassed. I am not trying to make a case for equality of income but I do feel that some people and some organisations are so rich that they could afford to put more into the national pot. I also feel that rewards for effort could be more sensibly distributed. I find it obscene that a pop singer can earn many times the income of a brain surgeon or that many people in local government in the UK earn much more than the salary of the Prime Minister. I feel that we are getting rather off topic so I will repeat the point that I originally made - I think that allowing the National Debt to increase year on year is dangerous and a sensible strategy would involve shrinking it year by year.

OK you now hold the record. Don't bother to reply with "I?". lol

Well, that's the shortest argument I've ever had lol. More seriously, if you think my post #42 is wrong then you must think the premise that lies behind my statement is also "wrong". As I see it in a democracy the government is elected by the People in order to run the country in accordance with the wishes of the People. This work necessitates the spending of money. If we discount the idea of printing money (which devalues all money in existence) the money needed must come from the People. If the money coming into the government's coffers and the money the government has to spend to meet the wishes of the People do not balance then I see only two sensible options for long term stability. The People must reduce their demands concerning what the government is expected to do or they must provide the government with more funds. Perhaps I am biassed in what I say next because (although I feel richer than America) I live on a very modest income. There are many people and concerns that are so rich that it is obscene. These people and concerns could probably bail out their respective countries if they so wished. They could certainly pay a lot more tax! I can see reasons why they would not wish to do that because the whole sorry mess would just start again.

IMHO the financial woes of both the UK and USA have a simple underlying cause. Governments who allow a national debt to increase year on year are building a house of cards that is destined to eventually collapse. The simple solution is to ensure that the national debt decreases, if only a little, year by year so that eventually over many years solvency can be obtained. The problem with this is that any government that takes the necessary steps to ensure this happens would become so unpopular that they would soon be voted out of office. I fear that this is a weakness of democracy and if "the house of cards" does collapse then democracy might collapse with it. I borrowed money earlier in my life to buy my home and sundry cars over the years but now I am retired I owe nobody anything. There was a newspaper headline the other day "Apple is richer than America". Since I am debt free I feel I can fairly claim that I, too, am richer than America!

In my younger years I must have picked the correct door since I am now retired and still living what I consider a rewarding life!

There are certainly creatures that glow like neon lighting. For example the fish called a Neon Tetra.