Physics review

Gambra

Only just finished it a while ago. Left an hour early. This was due to me dropping down to pass just yesterday. I did everything bar one question. I have no regrets doing Pass, saw the honours and though it was impossible!!

Zeuz

Did exactly the same , although I did not leave early I answered every single question, leaving early is not a good thing its only 3 hours out of your life

But yea i found it a bit diffferent not what I was expecting some of the stuff

Raphael

Did the honours, nice paper. Did Q1,2,4,5,6,7,8,9,10,12(a,b,c)

Experiments gave me a fright, didn't know the formulae involved for 1 or 3. Then I realised you didn;t need the formula for 1. Happy days!

NADA

Raphael wrote:

Did the honours, nice paper. Did Q1,2,4,5,6,7,8,9,10,12(a,b,c)

Experiments gave me a fright, didn't know the formulae involved for 1 or 3. Then I realised you didn;t need the formula for 1. Happy days!

Was a great paper. Experiments were easy 1,2,3 and then I did 5,6,7,9,10a,12(a and see). Looking at an a2 or maybe an a1

niamhy101

really nice paper, did 1,2,3,4,5,6,7,8,9,10,12 a,b,c

the experiments weren't all what i thought they would be, but ya cant predict them all!!

nedward

In the expt. with the spectrometer, what was the angle you were given? Was it between the two diffracted second order images, or between the zeroth order and the second order?

Good paper though.

whassupp2

grand paper. Dis 1,2,4,5,7,9,11,12(a,b and d)

Only hopin for C1/2

HoboJesus

nedward wrote:

In the expt. with the spectrometer, what was the angle you were given? Was it between the two diffracted second order images, or between the zeroth order and the second order?

Good paper though.

"The second order image on the left and the second order image on the right." Twas the two diffracted second order images.

nedward

Cheers. Thought that. Bloody stupid question.

exiot

Dropped down to pass because of my lack of studying, the big gap between exams really puts me off..

Pass was easy, nothing much to it. I laughed at Question 11, nearly all the answers were in the paragraph given.

Happy that I will never have to study physics again, one more exam left

Nichololas

some thread wrote:

f=ma guaranteed in physics

Guess not.

Enlil wrote:

Newton's Second Law and Speed of Sound in Air are tipped this year I think. I heard Verification of Joule's Law could also come up (last up in 2003).

2 out of 3 ain't bad.

Overall that went pretty good. Dropped maybe 10 marks in Section A (stupid "Find the resistance" :mad: ) The Electron only coming up in Q12 kind of limited my options for the rest of the paper. Did Qs 5, 8, 10a, 11, 12c and b. Only got 5/8 in 5 and didn't know some of the stretched string stuff in Q11. Otherwise nary a mark dropped. Give myself a B1 I'd say (I hope).

helles belles

Q1.why was a small heavy bob used?
Q.10 why were pairs of negative and positive pions produced?

whassupp2

helles belles wrote:

Q1.why was a small heavy bob used?

Because a big bob leads to air resistance and this slows down the movement of the bob. (thats what i sed. dunno is it right.)

Zoodlebop

whassupp2 wrote:

Because a big bob leads to air resistance and this slows down the movement of the bob. (thats what i sed. dunno is it right.)

Yea, I said that. I also said that it had to be heavy so that the string didn't go slack at the top of its swing.

It had to be inextansible to the the bob didn't perform SHM, right?

DiscoMouse

Ahahaha, I destroyed that paper! No surprises at all, avoided light completely, A1 easy. On to Chemistry!

EDIT: And I said the string was inextensible so the length remaing constant during oscillation.

whassupp2

Zoodlebop wrote:

It had to be inextansible to the the bob didn't perform SHM, right?

Doesnt the bob perform SHM anyway??? I said that its because its a relationship between period and length the length must be kept constant or some rubbish like that.

Nichololas

Well done DM.

Small heavy bob:
i) To keep string taut
ii) Reduce air resistance, as opposed to a large heavy bob.

Can't remember exactly why negative and positive pions are produced. Mass defect and conservation of charge springs to mind but I can't pinpoint exactly.

Zoodlebop

Did everyone derive the relationship between velocity and angular velocity by getting the length of the arc with radius r and angle Ø, then dividing that length by time. Angluar velocity=Ø/t and v=rØ/t

=> v=r(omega)

Q.12 (a) Did ye get something similar?

Pressure is scalar or vector?

Pressure at bottom = 3 x pressure at top

Lake depth = 20 point (something) metres

whassupp2

Zoodlebop wrote:

Pressure at bottom = 3 x pressure at top

Thats what i got. then i figured it must have somrthing to do with the 4 degrees so i changed it.

Rockerette

i thought it was a pretty ok paper, if i had been super studious, i woulda been grand. and in fairness i was grand. the usual, coulda do some bits, couldnt do other..


the experiments were lovely, did 1, 2, 3

Q5 was great, and Q12 was grand too


and from there, i wished i coulda just picked and chosen buts and pieces from teh rest.. hehe..


Did 6 (ahaha. ok, i did q6 based purely on the fact i knew the definitions.. for 12 marks.. did it at the end, i suck at circular motion, so i bet onyl 12 marks from that question...)
7 (gosh. it wasnt difficult, but it confussed me)
8 (knew about 1/2 of it.. guessed the rest :eek: )
11 (why didnt i learn amgnetic flux related stuff? bastard me)



So yeah, it was a grand paper, and for people who actually knew their stuff, i'd say they were flyin



i wanted a B2. dont think i got it. i'll be HOPEFUL and go B3, but hhmm.. might be bordering on C material the more i think about it...

Zoodlebop

Enlil_Nick wrote:

Can't remember exactly why negative and positive pions are produced. Mass defect and conservation of charge springs to mind but I can't pinpoint exactly.

Aren't those particles produced to conserve the energy with which the protons collide, by carrying it away as mass?

Damn, your right about the SHM. It is inextensible to keep the length constant. I may get some marks for "so it doesn't perform vertical SHM"

"Three negativly charged leptons"

Did ye know that?
I said electron, negetron and zion:rolleyes:

sully-gormo

That was a grand paper, was expecting it to be a bit easier but i still did ok.
Does anyone know?:
What are THE two negative leptons; I had a look through the book and I think that Q is wrong
Why are + and - pions produced??

Overall it was grand; hopefully I got the A1. I think anyone who was relying on a prediction did badly, that paper would have been impossible to predict

DiscoMouse

Zoodlebop wrote:

Aren't those particles produced to conserve the energy with which the protons collide, by carrying it away as mass?

Damn, your right about the SHM. It is inextensible to keep the length constant. I may get some marks for "so it doesn't perform vertical SHM"

"Three negativly charged leptons"

Did ye know that?
I said electron, negetron and zion:rolleyes:

LOL

It was only a passing mention in the chapter, but the other two negative leptons are the muon and the tau electron.

Zoodlebop

Overall I thought it was a luvly paper.

For Q.2 did you divide the given angle by two to find the angle to put into

n(lambda)=dsinØ

????

Rockerette

DiscoMouse wrote:

LOL

It was only a passing mention in the chapter, but the other two negative leptons are the muon and the tau electron.

SCORE!

i actually got soemthing right... ahahahahaa.. woo

Nichololas

Zoodlebop wrote:

Aren't those particles produced to conserve the energy with which the protons collide, by carrying it away as mass?

Damn, your right about the SHM. It is inextensible to keep the length constant. I may get some marks for "so it doesn't perform vertical SHM"

"Three negativly charged leptons"

Did ye know that?
I said electron, negetron and zion:rolleyes:

Actually that's what I meant by mass defect, the difference in the energy/mass from the beginning and end of the equations. I said conservation of charge because that's why there's a negative AND a positive pion.

And talking of silly answers, the experiment to verify Newton's 2nd Law must have been weighing heavily on my mind because I drew that diagram instead of the Joule's Law one. I was confused when I read over the paper, thinking; "Where the **** did that come from", then frantically scribbing it out and drawing in the right one. Infact that's less silly more full on retarded. The examiner's going to think I'm a retard. :cool:

Raphael

It's cool man, we ALL think you;re a retard. =p

sariane

in the first experiment did u have to divide t by 25 first and then square it??? i completely forgot to divide by 25 cos i didnt think u had to!!

Zoodlebop

Enlil_Nick wrote:

Actually that's what I meant by mass defect, the difference in the energy/mass from the beginning and end of the equations. I said conservation of charge because that's why there's a negative AND a positive pion.

I'm not sure about that.....I thought that all the mass defect all went into the energy of the gamma rays, otherwise how would you know what mass went into the gammas and what went into pions. I think that the collision energy of the protons is converted into mass, mass in the form of pions. I'm not positive though. Sure 'tis only 6 marks What did you say for why 2 photons are produced? I said that the energy produced from the 2 protons is two great to be carried away by one photon.

OctavarIan

Physics... made the mistake of not changing to ordinary on the day, totally got ****ed up the ass in the hons paper.

Nichololas

sariane wrote:

in the first experiment did u have to divide t by 25 first and then square it??? i completely forgot to divide by 25 cos i didnt think u had to!!

Uh I hope not because I don't do that either. I got a straight line graph though.

Rockerette

you did have to do didnt you??
to get the time for 1 oscillation??

please tell me you did.

im prettt sure, but sure, im just a girl, so dont trust me

sariane

yeah i read the kind of introduction thingy at the top of the first question after and it said the time t for 25 osicalltions was recorded.... i managed a straight line graph though aswell

Rockerette

yeah but the X axis will still be proportioned, forming a straight line through the origin, whethere or not you divided them all by 25..

Rockerette

yeah but the X axis will still be proportioned, forming a straight line through the origin, whethere or not you divided them all by 25..

Dave Larkin

I thought it was pretty good. The experiments were reasonable. Overall a grand paper.

NADA

You have to divide by twenty five indeed. I did not divide the given angle by two but when I was looking at it I thought that's what they meant. Then just assumed they couldn't and said sin41.5. oh well! I loose about 5 marks.

sully-gormo

You have to divide by 25.
Then you plot either t and root(l) or t(squared) and l
You had to divide the angle by 2
you got 2(lambda)=dsin20.3
For d you had to invert it[1/300] and multiply it by ten to the power of -3(to get the distance between the slits in meters

I said the string was inextinsible because you want it to oscillate in one plane only; or something to that effect

Go to maddox.xmission.com to forget about that exam. Read the one at the end about childrens artwork

Rockerette

NADA wrote:

I did not divide the given angle by two but when I was looking at it I thought that's what they meant. Then just assumed they couldn't and said sin41.5. oh well! I loose about 5 marks.

F!uck.




gah.

stOOpid me, i never divided the angle either.

bollocks.

The Agogo

in q6, What were the forces acting on the ball?

in q8, the isotope of helium is 3/2HE right?

in q12a,the pressur at the bottom of the lake is three times 1.01x10^5?

and finally, Q12d, how do you calculate the energy of the electron when it passes thru 50Kv?

i think i did ok, but i dont want to hedge my bets.

The Agogo

Rockerette wrote:

you did have to do didnt you??
to get the time for 1 oscillation??

please tell me you did.

im prettt sure, but sure, im just a girl, so dont trust me

ye you had to divide by 25 for one oscillation and then square t

i ****ed up in the Q1 cos i thought it was the formula g=2s/t squared, so i squared t and doubled s. shoit

The Agogo

Rockerette wrote:

you did have to do didnt you??
to get the time for 1 oscillation??

please tell me you did.

im prettt sure, but sure, im just a girl, so dont trust me

ye you had to divide by 25 for one oscillation and then square t

i ****ed up in the Q1 cos i thought it was the formula g=2s/t squared, so i squared t and doubled s. shoit

helles belles

The Agogo wrote:

ye you had to divide by 25 for one oscillation and then square t

i ****ed up in the Q1 cos i thought it was the formula g=2s/t squared, so i squared t and doubled s. shoit

thats what i did too!
do you not have to do it???

Kovik

I thought it was relatively okay until I realised how I ****ed up the question about the lenses. That was forty marks gone right there.

Rawr. I was looking for a B2, not sure if I'll make it now.

Kovik

Bonus for Gaeilge, I summon thee to my aid...

Raphael

"STFU agus Léim sios tubair" arsa an Bonus
"Bollocks." arsa Kovik. "Táim fucked anois"

Kovik

;_;

Feral Mutant

I said that pions are produced because the photons experience pair production forming quarks and their antiquarks. As mesons, pions are made of a quark and an antiquark.

fatal

what a ****in paper...im over the moon...i did every question except for 9 and 11,the electricity ones...so much easier than i expected it to be