mephistowaltz

Hi,

Like everyone, I have a large jar full of loose change in my house. So today I tipped all the coins out and started counting them. The jar was full of all the different denominations of coins (i.e, 1c, 2c, 5c, 10c, 20c, 50c, €1, €2).

Just by guessing I'd say the jar was about 1/3 full of 1 cent coins (with all the other denominations making up the other 2/3).

After counting them it turned out I had exactly €10.01 in 1 cent coins (i.e, I had exactly 1001 one cent coins in the jar).

My question is:

Is it possible to calculate the odds of having exactly €10, in 1 cent coins, in a jar filled with all the denominations of coins?

Or it the only way of determining the amount of one particular coin by guessing?

The volume of a 1 cent is roughly = 3.46 x 10^-7 m^3,

The volume of the jar is = 7.03×10^-4 m^3

Hi,

I've heard that when a fridge compressor kicks in it can cause a major voltage drop across the main breaker in a house. This can cause modern TV's to go black for a few seconds.

Now, sometimes when I open my fridge the power cuts out to it (as if its been plugged out), I suspect its the socket as its kinda lose and sometimes makes a small 'electrical' buzzing!

Also, for clarification, when the TV cuts out, it happens when I watch DVD's or play video games (which are connected using a HDMI cable). I dont have TV channels so it's not a RF or digital signal interference, its purely electrical.

Should I be worried about dodgy wiring or the half broken socket?

Or is it just a voltage drop when the compressor on the fridge kicks in?

Hi,

I'm looking for some details on what exactly happens when you connect 2 speakers to 1 output in a stereo HIFI system? I have a few questions.

1) Am I right in saying if you wire them in parallel then you double the load so the impedance would be halved? (i.e., the impedance is split between the 2 speakers)

2) And in series the impedance would be doubled?

3) Also; if the impedance is halved then would it not be possible to easily overload the HIFI?

4) And if its in series then, due to the higher impedance, it would adversely affect the sound?

The other issue I have is:

5) If i just stick the cable from speaker number 2 into the output on the back of the stereo (i.e., into the same output that speaker number 1 is already in)... is that in parallel or series?

Finally:

If 2 speakers are connected to the same output then would the final volume be greater or stay the same? (My gut is telling me the volume would be unchanged!)

Any help at all would be great,

Thanks!!

My local library is divided into multiple rooms, with both an upstairs and a down-stairs. It has wireless internet through-out the entire building except one room on the upstairs floor, the 'meeting room'.

The room isn't tucked away at the back of the building or anything, in fact it's the 1st room at the top of the stairs! There are rooms which are farther away (and around more corners) from the router but the internet signal is perfect in every other room, except the meeting room!

Somebody who works there told me that they even had some type of engineer out to figure out why there was no signal in that room but couldn't figure it out!

Mobile/cell phones work perfectly in the room and Mobile internet (i.e., the internet on your phone) works fine too! But for some reason we can't connect iPads to the library's internet in that room (we didn't try a PC or laptop, we only tried with iPads)

Could high voltage cabling behind the walls be affecting the signal -- or some other type of environmental factor?

Or could this be an iPad specific problem?

Any suggestions as to why this is happening?

Simple enough question.... which of these is correct?

I have never written about food before!

or

I have never wrote about food before!

Im sure it must be 'written' but I need confirmation about which is correct!

Hi,

I have two questions concerning the onion router (TOR);

i) When using TOR, it changes my IP address. If the exit node wanted to check my IP, would they see the altered IP or my original IP?

ii) When watching Flash videos (e.g., YouTube) or using Java Script (or other third party browser plugins) they run as my user account with my permissions in my operating system. Does that mean that they, potentially, can bypass TOR and share my information?

Also if, say, YouTube did bypass TOR, would they see my original IP or my TOR altered IP?

Thanks in advance!

Hi,

Here's what Im trying to describe, Ive written it out in steps to be as clear as possible:

i) I've taken the numbers n = 1,2,3,...,10.

ii) Then Ive split them into 2 sets, each with 5 numbers.i.e.,

A = {1,2,3,4,5}

B = {6,7,8,9,10}

iii) Then I've summed up each consecutive term in each set. i.e.,

Taking set A we get:

(1 + 2) = 3, (2+3) = 5, (3+4) = 7, (4+5) = 9

which gives another set C = {3,5,7,9}

[for set B the resulting set is D = {13,15,17,19}]

iv) Then I've summed each consecutive term in sets C and D, i.e.,

Taking set C only we get:

(3+5) = 8, (5+7) = 12, (7+9) = 16

which gives the set E = {8,12,16}

[for set D we get set F = {28,32,36}]

v) And again Ive summed the consecutive terms in sets E and F to get another 2 sets G and H:

G = {20, 28}

H = {60, 68}

vi) and once more ive summed the remaining terms to get 2 more sets:

I = {48}

J = {128}

This in sequence is just: 48,128

vii) Now if n = 1,2,3,...,20

and if we follow the above method for this set of values for n we end up with the sequence:

48, 128, 208, 288

This is equivalent to: 80 x − 32

What Im trying to do is describe the steps (i) - (vii) in mathematical terms?

Hi,

If you write out all the solutions for the sum √ [4(n)] (i.e., the square root of 4 times n), you get a sequence of numbers.

where; 0 <= n <= X,

Most of the numbers in the sequence are irrational but every now and again a whole number pops into the sequence.

An example of the sequence is below. (in the example i have set:

irrational numbers = O

whole numbers = 1)

1,1,O,O,1,O,O,O,O,1,O,O,O,O,O,O,1,...

As you can see from the above example; the whole numbers fall on the:

1st, 2nd, 5th, 10th and 17th (etc) iteration of the formula √ [4(n)].

Therefore the sequence of numbers i end up with from the iteration of √ [4(n)] is:

1,2,5,10,17,...

What I am trying to do is word, mathematically, the process I have just done above? i.e., Im trying to describe, mathematically the following steps:

i) Iterate the formula √ [4(n)] X amount of times.

ii) From those results, see which of the answers is a whole number.

iii) create and describe a sequence based on the positions of the whole numbers in the sequence of results of √ [4(n)]

************************************************NOTE**********************************************

The sequence of numbers that you get from noting the positions of the whole numbers in the sequence of the results of √ [4(n)], i.e.:

1,2,5,10,17,...

is defined by:

n²+1

but this result isn't exactly what im trying to describe! What I need help with is trying to describe that the whole numbers fall on the 1st, 2nd, 5th etc iteration of the sum?

Hi,

I own an old 100W Marshall valvestate amplifier. It hasn't worked in years but recently I opened it up to take a look, in the hope that I could fix it.

However upon taking it apart I noticed that the circuit board was covered in a hard foam-like substance!?

The foam-like substance was very much like 'expanding foam' (i.e., the stuff builders use to fill gaps in walls etc). It was a brownish colour, porous and hard to the touch, but it was easily breakable (I could chip away at it using my fingernails)

There looks to be a fairly large capacitor on the circuit board, from which it appears that the foam has emanated from, but I cant be sure as the foam has literally covered all the components on the board!

Furthermore a blown capacitor wouldnt spew a foam that hardens??!!

1) What's going on with this circuit board?

2) Any suggestions as to what this foam is or how it got into the amp? (Is it put there intentionally as a heat sink or something crazy?)

Also the amp used to work but over time it started to cut out until one day it stopped working completely!

Hi,

I own an old 100W Marshall valvestate amplifier. It hasn't worked in years but recently I opened it up to take a look, in the hope that I could fix it.

However upon taking it apart I noticed that the circuit board was covered in a hard foam-like substance!?

The foam-like substance was very much like 'expanding foam' (i.e., the stuff builders use to fill gaps in walls etc). It was a brownish colour, porous and hard to the touch, but it was easily breakable (I could chip away at it using my fingernails)

There looks to be a fairly large capacitor on the circuit board, from which it appears that the foam has emanated from, but I cant be sure as the foam has literally covered all the components on the board!

Furthermore a blown capacitor wouldnt spew a foam that hardens??!!

1) What's going on with this circuit board?

2) Any suggestions as to what this foam is or how it got into the amp? (Is it put there intentionally as a heat sink or something crazy?)

Also the amp used to work but over time it started to cut out until one day it stopped working completely!

Which is the correct way to say the following:

'The group and I (are/am) going to the shops.'

Should it, in fact, be said: 'Me and the group are going to the shops'

???????????????????

Im actually looking for the similarities between the formation of Be-10 (spalling) and how the LHC makes isotopes...

I know a bit about Be-10 already but what im really wondering is how isotopes are made at the LHC

Im pretty sure they bombard elements with protons and neutrons but any additional details would be great

I am a native English speaker and I am learning a second language (what Ive really learned is that I don't even know English that well! ).

Part of the course is to translate sentences from English to the other language. To do this correctly I have to first know what/who the subject and the object is of each sentence in English. I have a fair idea of the difference between the subject and object and I have no problem with straightforward sentences like:

The boy will have cake,

The boy = subject

cake = object.

But I am getting confused on the following sentences:

1) We don't have paper.

2) her old friend didn't write.

3) You will met their old friends.

4) Your new teacher forgot your book.

5) The boys hate our new teacher.

What is the subject & object of the previous sentences?

When looking at the footage from the SOHO satellite you constantly see stuff streak across the image.

Is this just static interference, or meteors, or charged particles?

what is it?

Hi,

I heard a rumor about the origins of the word 'wake' (as in a funeral wake) and etymology aside I didnt believe the fact! The basis of It said:

Drinking alcohol from lead cups used to knock people out, sometimes for many hours or days!!!

My question is:

i) What would be the effects of drinking strong alcohol (whiskey etc) out of a lead cup on the human body? (If it was done on a regular basis)

ii) Would it even be possible for lead + alcohol to knock you out for a day/s?

Thanks

Hi,

I heard a rumor about the origins of the word 'wake' (as in a funeral wake) and etymology aside I didnt believe the fact! t=The basis of It said:

Drinking alcohol from lead cups used to knock people out, sometimes for many hours or days!!!

My question is:

i) What would be the effects of drinking strong alcohol (whiskey etc) out of a lead cup on the human body? (If it was done on a regular basis)

ii) Would it even be possible for lead + alcohol to knock you out for a day/s?

Thanks

Hi

over the last 6 months or so I have been battling with insects in my bedroom! When it started I was roughly being bitten once a day (usually around the ankles). I tackled the problem by washing everything in my apartment/ hoovering (vacuuming) everywhere everyday and generally scrubbing the place clean.

This kind of worked and the biting stopped for a while. But every now and again I get bit.

The bite looks like:

a raised swelling on the skin, slightly paler than my skin and itches like hell.

There is never any sign of blood or a bite puncture in my skin AND usually I get bitten several times in the 1 attack. After a few days the bite mark turns dark red and continues itching.

I caught one of the insects biting me one day and it looked like a FLEA. It jumped away from me like a flea but i managed to squash it. My questions are:

i) From what I described do you think its fleas that are biting me? If that is the case then why am I only getting bitten every now and then? I read that fleas multiply in massive numbers, so I would imagine if it was fleas then I would be over run by them by now?

ii) If it is fleas, then how do I get rid of them?

p.s I live in Ireland so we dont have that many biting insects over here! I also live in a very small apartment with no carpets (ive heard fleas like to hide out in carpets) and no pets!

Hi

over the last 6 months or so I have been battling with insects in my bedroom! When it started I was roughly being bitten once a day (usually around the ankles). I tackled the problem by washing everything in my apartment/ hoovering (vacuuming) everywhere everyday and generally scrubbing the place clean.

This kind of worked and the biting stopped for a while. But every now and again I get bit.

The bite looks like:

a raised swelling on the skin, slightly paler than my skin and itches like hell.

There is never any sign of blood or a bite puncture in my skin AND usually I get bitten several times in the 1 attack. After a few days the bite mark turns dark red and continues itching.

I caught one of the insects biting me one day and it looked like a FLEA. It jumped away from me like a flea but i managed to squash it. My questions are:

i) From what I described do you think its fleas that are biting me? If that is the case then why am I only getting bitten every now and then? I read that fleas multiply in massive numbers, so I would imagine if it was fleas then I would be over run by them by now?

ii) If it is fleas, then how do I get rid of them?

p.s I live in Ireland so we dont have that many biting insects over here! I also live in a very small apartment with no carpets (ive heard fleas like to hide out in carpets) and no pets!

my bedroom often stinks! you might imagine that the solution to this would be to open my window to 'air' out the room..........BUT

I have found that opening it has little effect!

I live in a walled off area so very little wind actually 'passes' by my window, even on a very windy day if i stick my head out the window i will barely feel anything.

If i open a window in an adjacent room a weak breeze will blow through but i guess my real question is:

why wont my room air out from just opening the bedroom window?

Also if my room is very hot and i open the window the problem still persists! I assumed (obviously incorrectly) that due to it being significantly colder outside, and if my room is hot, then due to the pressure difference the hot air will flow out the window!

This doesnt seem to be the case where Im living now and the room will stay warm for a very long time after opening the window..... whats going on?

Why does the air rushing past you from the wind or a ceiling fan keep you cool if , what is happening is, the air is accelerating past you?

When its hot the atoms/molecules in the air experience an increase in velocity, so how come when they accelerate past you it feels cold?