Pop Quiz

JC 2K3

Haven't a Clue wrote:

Irish: What the hell is An Bhean Óg about?

Essentially nothing to those currently sitting the LC. There're very subtle undertones that tell of the way society was back then which are only truely understandable if you were from that time and hence I can't comprehend why they put such a boring and pointless text on the LC.

Haven't a Clue

Rozabeez wrote:

Because he didn't want an immediate war upon Ireland, or whatever that quote was, he knew 26 counties was the best they'd be getting.

More history, also easy: State Hitler's foreign policies.

I'm not sure, but I use the four main things out of Mein Kampf: Grossdeutchland, Ayran Race, Third Reich and I don't seem to remember the fourth. Don't take this at gospel though, it's just what's coming to me head now...

eZe^

JC 2K3 wrote:

Area of the plates' overlap, Permittivity of the medium between the plates and area between them.

(C = (Epsilon)A/d)

App Maths: If you push two identical cats off a roof witht he same force, with both of them the same distace form the edge, which one hits the ground first?

The stupider one?

Spank wrote:

A young woman, her isolation, her kids, and something about their dead beat dad.

Name a chemosythic and photosynthic bacteria.

Chemosynthetic = Nitrogen fixing bacteria in nodules in plants
Photosynthetic = Rhodospirillum


Physics ;
Describe the principle on which a refridgerator operates.

Rozabeez

Haven't a Clue wrote:

I'm not sure, but I use the four main things out of Mein Kampf: Grossdeutchland, Ayran Race, Third Reich and I don't seem to remember the fourth. Don't take this at gospel though, it's just what's coming to me head now...

Lebensraum iirc.

tolosenc

eZe^ wrote:

Physics ;
Describe the principle on which a refridgerator operates.

Something about pressure in a liquid that is pumped around the fridge?

JC 2K3

eZe^ wrote:

The stupider one?

Nah, the one with the lower "Mew" (Mu).

eZe^ wrote:

Physics ;
Describe the principle on which a refridgerator operates.

Heat is transferred from the inside of the fridge to liquid/gas inside a pipe running into it from the outside which is constantly being pumped in and out of the refridgerator and being condensed and expanded in order to lower the temperature of the fridge. It's based on the principle that Pressure is proportional to Temperature.

Rozabeez

Refrigerators work on the principal of evaporating. Heat is drawn from inside the ridge during evaporation. Special type of liquid called refrigerant is used, can easily be evaporated to a gas and condensed back to liquid again.
<insert diagram here>
Compressor at base of fridge is activated by electric motor.
Forces regrigerant into condenser.
Regrigerant is cooled by condenser and chanced into liquid.
Liquid passes from condenser into evaporator where it is cooled and evaporated into gas.
Liquid refrigerant evaporates by removing heat from inside the fridge.
The evaporated refrigerant returns to the compressor and the cycle begins again.
The temp is controlled by a theromostat.

^ That's a Home Ec answer, don't do Physics, sorry!


hmmm... Economics: Define privatisation and the reasons for it.

sternn

Rozabeez wrote:

hmmm... Economics: Define privatisation and the reasons for it.

Dont do economics but from business...

Privatisation is when the government sells off a company which it owns.
They do this to let the company expand and create more jobs, and to stop spending the tax-payers money on their wages!!

Physics: State newtons 3 laws...

cson

examples - Aer Lingus and Telecom Eireann -> Eircom Plc.

JC 2K3

1. A body's velocity will remain constant unless a force is applied to it.
2. Force is directly proportional with the rate of change of momentum of a body.
3. When a body, A, puts a force on another body, B, B puts an opposite and equal force, a reaction force, on A.


Chemistry:: Define Electronegativity.

cson

Electronegativity > The relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond.

Q - At room temp, chloroform (CHCl3) is a liquid but Methane (CH4) is gas, suggest a reason for this.....

boger

economics: wats NAIRU

sternn

boger wrote:

economics: wats NAIRU

Again dont do economics but know it anyway.... Non accelerating inflation rate of unemployment

Geography: Name the factors that affect soil characteristics.

JC 2K3

cson wrote:

Electronegativity > The relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond.

Q - At room temp, chloroform (CHCl3) is a liquid but Methane (CH4) is gas, suggest a reason for this.....

Not 100% sure but is it that CH4 is non-polar and therefore only has weak Van der Waals intermolecular forces as opposed to CHCl3, which is a polar compound and therefore has stronger Dipole Dipole intermolecular forces?

md99

boger wrote:

economics: wats NAIRU

Never heard of this boger, what makes you think it'll come up?

As regards economics, how bout... Balance of Autonomous Transactions? Purchasing Power Parity Theory?

dan719

Balence of autonomous transcations is all official trade between two countries managed so as to keep currency exchange rates at a certain agreed level.

ppp-the now defunct theory that currency rates will stabilise at such a level so that a unit of currency willl buy the same quantity of a good no matter where it is bought.econ is a real joke of a subject really!:D

No one has answered my question abot orwell and keynes, what do they have in common???;) And its not that there english!

tolosenc

I really don't know Dan. Something about India, maybe? Do tell.

dan719

Both went to eton, but orwell failed to get his exams so went off to join civil service instead of heading to uni! do I get to ask another one??

okay proof any system that obeys hookes law is simple harmonic motion!:D

edit-so many typos damn study

tolosenc

F=-ks => ma=-ks => a=-(k/m)s , ie a=-(w^2)s, where w^2=(k/m)
Therefore, the system moves with SHM.

Geography: What's the average size of a farm in the Beauce region of the Paris Basin?

JC 2K3

Are systems that obey hookes law not in SHM by virtue of obeying hookes law?

I mean is SHM not defined by a being proportional to -s and hookes law not F = -ks ?

Therefore ma = -ks and a is proportional to -s....

strange question....

dan719

JC 2K3 wrote:

Are systems that obey hookes law not in SHM by virtue of obeying hookes law?

I mean is SHM not defined by a being proportional to -s and hookes law not F = -ks ?

Therefore ma = -ks and a is proportional to -s....

strange question....

But there is a proof of same. i.e deriving shm formula in full form hookes law.

boger

watsbthe capital of argentina

JC 2K3

Buenos Aires.

Maths: Integrate (secx)^4 dx

tolosenc

{(secx)^4.dx = [(ln|secx+tanx|)^5]/5 +c

JC 2K3

Wrong.

I dunno what you've done there, looks like you've tried to apply the chain rule to integration or something....

tolosenc

Yeah, I dunno what I was doing either. Try this:

1/3(tan[x]sec^2[x]) + 2/3{sec^2[x].dx
=>1/3(tan[x]sec^2[x]) + 2/3(tan[x]) + c
=> 1/3(sec^2[x] + 2)tan[x] + c

Better?

JC 2K3

Yup,

To simplify it a bit:
1/3(sec^2[x] + 2)tan[x] + c
sec^2[x] = 1+ tan^2[x]
1/3(tan^2[x] + 3)tan[x] + c
(tan^3[x])/3 + tanx + c

Integration by parts yeah? Check out this much simpler way:

Use the identity: sec^2(x) = 1 + tan^2(x)

Int [sec^4(x) dx] = Int [(1 + tan^2(x)).sec^2(x) dx]

Substitution:
u = tan x
du = sec^2(x).dx

Int [1 + u^2 du]

= u + (u^3)/3 + c

= tan x + (tan^3(x))/3 + c


Got the inspiration for the question from this thread. As you'll see, I also did the longer integration by parts method....

analyse this

Maths

Prove De Moivre's: Prove (CosO +iSinO)^n=Cos nO+iSin nO

Haven't a Clue

JC 2K3 wrote:

Yup,

To simplify it a bit:
1/3(sec^2[x] + 2)tan[x] + c
sec^2[x] = 1+ tan^2[x]
1/3(tan^2[x] + 3)tan[x] + c
(tan^3[x])/3 + tanx + c

Integration by parts yeah? Check out this much simpler way:

Use the identity: sec^2(x) = 1 + tan^2(x)

Int [sec^4(x) dx] = Int [(1 + tan^2(x)).sec^2(x) dx]

Substitution:
u = tan x
du = sec^2(x).dx

Int [1 + u^2 du]

= u + (u^3)/3 + c

= tan x + (tan^3(x))/3 + c


Got the inspiration for the question from this thread. As you'll see, I also did the longer integration by parts method....

...and that, ladies and gentlemen, is why I'm doing ordinary maths now.

JC 2K3

Prove (CosO +iSinO)^n=Cos nO+iSin nO
I'm gonna use A instead of O

when n=1
(CosA + iSinA)^1 = Cos(1)A + iSin(1)A

Therefore (CosA + iSinA)^k = CoskA + iSinkA is true for at least one value of k.

If n = k+1
(CosA + iSinA)^(k+1)
(CosA + iSinA)(CosA + iSinA)^k
CosA(CosA + iSinA)^k + iSinA(CosA + iSinA)^k

And since: (CosA + iSinA)^k = CoskA + iSinkA

CosACoskA + iCosASinkA + iSinACoskA - SinASinkA
(CosACoskA - SinASinkA) + i(SinACoskA + CosASinkA)
Cos(A + kA) + iSin(A + kA)
Cos((k+1)A) + iSin((k+1)A)

Therefore (CosA + iSinA)^(k+1) = Cos((k+1)A) + iSin((k+1)A)
And therefore (CosA + iSinA)^n = CosnA + iSinnA for all values of n.