Physics

PHB

How'd it go.
I though it was a lovely paper!

The_Keeper

yea it was a pretty good paper

i feel i answered everything correctly but physics always seems to find a way to screw me over... but i'm confident i'll get at least 70+

section A was very nice

Q5 was good
Q7 - sound was great

Q11 + 12 were also very nice

Q10 - options looked horrible so i avoided it

Q6 was also an easy question

so over all dam good paper

Tazzle

/me makes retard gestures

DSMe

ah ****e... i thought there was 100 ... u know milisomething is usually 100

Sev

Most perfect paper yet as far as I'm concerned, answered every question perfectly except part (c) and (d) of question 12, didnt have time to finish those. I'm kicking myself tho cos I didnt spot the final 6 mark part to the sound question tho, goddamn it. No matter how many times I look over the paper....

I'm glad I remembered Stoney too, for that electron question.

Sev

A millisecond is a thousand of a second, as is millianything. Milli means x 10^-3.

Boston

Very good, thought it was excellent, i had to laugh when 1/u +1/v question came up after yesterday. Also i believe eireboy will have some egg on his face "boyles law wont come up in section a"

One thing thought, why does the sky driver achieve terminal volocity, i could have explained it use differenciation and then said as t tend towards invinity and all that crap but it seem to be to difficult for physics. I to remembered stoner.

Btw i started all my scales from o

eirebhoy

Physics was my best paper this year. I got about 75-82%. I found Q10a a bit hard though. The experiments were super Q5 was easy. But in Question 6 It asks "Describe an Experiment to find the resultant force of two vectors", I described the sum of the ups on a metre stick equal the sum of the downs, is that what your supposed to do?

Also, what is the difference between temp and heat?

Sev

Originally posted by Boston
Very good, thought it was excellent, i had to laugh when 1/u +1/v question came up after yesterday.

Yeah, also kinda ironic that no graph was asked for it, after all that fuss about graphing it yesterday.

Darth_Jman

'twas a very nice paper indeed.
Radiation was a joke of a question!
The only things I didnt get was guy who named the electron (damn you, Stoner! Should have made your name easier to remember!), and the experiment for showing sound is a wave. I know you could have put down the speed of sound one, or any of the sonometer ones (arguing why its valid etc), but in the end I made up one with an oscilliscope and a microphone. Do experiments, per se, have to *be* on the course to get marks for these types of questions?

Apart from that, one damn fine paper. A no bother!

Sev

For that terminal velocity question, I said that the force of air resistance is dependent on the velocity of the diver, and as his velocity increases there comes a point at which the air resistance is equal to his weight, so there is no longer a resultant force and he no longer accelerates downwards but remains at a constant velocity.

I did a great picture for that question, I hope I get bonus marks for my artwork.

PHB

Yeah I did the same ste.

Air resistance is proportional to velocity, so a terminal velocity is reached once the air resistance is equal to 90g

CuLT

Substantially better than I thought it would be, still, can't really tell how I did .

Sev

For the experiment showing sound is a wave, I wasnt sure exactly what one to do, couldnt remember if there were any better demonstrations in the book. Anyway I did the demonstration to show that sound undergoes constructive and destructive interference and is hence a wave in nature. The one with the speakers placed apart emitting same frequency. Not too bothered about that question tho, I have 7 other Section B questions answered perfectly to choose from.

Neil3030

Physics was a P155!!!

Section A - Ok, Joules law, boyles law and the focal length of a converging lens??? PISS EASY!! JC STUFF!!

Section B - Q5 was a stroll in the park!! Q6: Vectors! Perfect question. Then The Doppler effect and waves in Q7!! Question 8 was dead handy, all just graphs and no theory!! And question 12!!! HA!! thermometric properties and electromagnetic induction!!!

100 points in my back pocket baby!!!

Boston

Originally posted by Sev
For that terminal velocity question, I said that the force of air resistance is dependent on the velocity of the diver, and as his velocity increases there comes a point at which the air resistance is equal to his weight, so there is no longer a resultant force and he no longer accelerates downwards but remains at a constant velocity.

I did a great picture for that question, I hope I get bonus marks for my artwork.

You two lads do applied maths? This is exactly what i thought, but then i said it can't be because A) no mention of weather or not to take into account air resistance b) What your taking about is that acceleration = v dv/ds which is applied maths and not on the physics course, so i don't know how they would except an average physics sudent to get that. I'd say you would get most marks for the diagram and few for the explaination. I did A B and C any so it didnt really matter

Sev

Oh, for the resultant of two vectors, I think they intended you to use that demonstration in the book with the 3 interconnected spring balances, the magnitude of the force on one balance, being the vector sum of the other two forces. Anyway, thats what I said.

Boston

Originally posted by Sev
For the experiment showing sound is a wave, I wasnt sure exactly what one to do, couldnt remember if there were any better demonstrations in the book. Anyway I did the demonstration to show that sound undergoes constructive and destructive interference and is hence a wave in nature. The one with the speakers placed apart emitting same frequency.

That is the one your ment to do, i did it, though you would have to meantion that they had the same wave lenght

Sev

Yeah, I'd agree. That was a comment I made coming out of the exam hall, that the question was very applied mathsy.

Same frequency => same wavelength. I think I'll get by on that one. Either way, I'd say its more about the frequency than the wavelength, unless you start mentioning that one wave is moving faster than the other, which isnt going to happen.

After all the definition of coherent source is based on the fact they have the same frequencies and are in phase or have a constant phase difference.

pseudonym

physics woz lovely, got an extra q done and had time to spare

Neil3030

I just did the one where you hold the struck tuning fork over the microphone connected to the oscilliscope.

Boston

Originally posted by Neil3030
I just did the one where you hold the struck tuning fork over the microphone connected to the oscilliscope.

And what did that prove? isn't that just to get the frequency of the tuning fork, which isn't even an experiment of our course, but is on the a levels. How do you get the frequency? its writen on the side of the tuning fork!

Darth_Jman

Thats what I did (just didnt have a tuning fork).
If you make a sound, you see its waveform on the oscilliscope screen, which is a) a sine wave and b) in the form of a transverse *wave*

Sangre

Frequency for a tuning fork is written on it.

You could strike a tuning fork and then twist it near your ear showing interference.

The only I didnt get was that Stoney guy.
A1 me thinks.

Sev

The marking scheme can be quite broad in its range of accepted answers. I wouldn't rule that out altogether.

For example last year, you were asked to describe an experiment to demonstrate the photoelectric effect. Now the typical textbook demonstration is the one with the zinc plate on the negatively charged electroscope being shined with UV light.

But they also accepted, and gave full marks for, the one involving the set up of a circuit with a photocell (the one used to prove that the current produced is proportional to light intensity) as an acceptable experiment to use. I used the latter as an answer in my mock paper, and my physics teacher barely gave me any marks for it that scabby bastard.

Darth_Jman

Either way though, I dont thing it will be counted. If anyone has read the marking schemes for any physics paper, they list answers to those types of questions. Depends on the examiner you get I suppose

Neil3030

I read somewhere that it was acceptable. I completely forgot about the interference experiment so i decided to go with the oscilliscope one.

PHB

A) no mention of weather or not to take into account air resistance

I would assume you just sasume there is air resistance, as you are not told otherwise.
There is no other way to explain terminal velocity except assumign there is air resistance, or is there :P

Non the less, I did all four parts anyway

Sev

What's funny is, that just last night I was telling SOL about Question 11, the story question, the one that says "Read the following passage and answer the following questions" and about how every time I end up finishing question 11 in an exam, I ask myself why I bothered to waste my time to read it in the first place, its always so goddamn irrelevant.

Anyway, as it happens, I flew through that question in about 5 minutes, completely forgetting to read the paragraph in the first place, only glancing up for a second to spot the figure for the half-life. What a stupid, stupid question.

eirebhoy

Oh, for the resultant of two vectors, I think they intended you to use that demonstration in the book with the 3 interconnected spring balances, the magnitude of the force on one balance, being the vector sum of the other two forces. Anyway, thats what I said.

in Question 6 It asks "Describe an Experiment to find the resultant force of two vectors", I described the sum of the upward force on a metre stick equal the sum of the downward, is that what your supposed to do?

Please put my head to rest and tell me if the Metre stick explaination would be acceptable and able for full marks!

Sev

It sounds wrong, I couldn't tell you how wrong tho.

Boston

Originally posted by eireboy
Please put my head to rest and tell me if the Metre stick explaination would be acceptable and able for full marks!

Completely wrong, and most definitely not what they where looking for, but you will get full marks for it, providing you made the relavent points. Its basically the same experiemnt as the spring one, except larger. All you had to say was the the stick isn't moving therefore the vector sum of the forces acting on the body is zero, thats one of the principles of that experiemnt and i says that is what 99% of people did, its what i would have done as well if there wasn't an easier question. That bat question was great.

Shelliestar

i thought it was an..interesting paper, ive done easier and harder.
when i opened it i thought it was nice, then half way through i thought i was doing ****, but then near the end i started doing much better. Id say B2-A2, somewhere in there

oh and for the wave motion of sound, i put a tuning fork against a ripple tank, it produced ripples in the water etc
basically i made it up
couldnt find it in the book, id say theyll take a whole bunch of answers. theyre kinda desperate to get people to do phyics so they mark them fair, and not mean like in some other subjects

anyways im finished all my exams, woohoo, im headin into town
good luck to the rest of yous

ella minnow pea

dat was v v nice!
maths in it was so easy, and i got away with barely doing mechanics or electirity!

ITS OOOOOOOOVER!!!!!!!!!!!

Bottle_of_Smoke

how fast was the bat travelling??????


Q7 i think

Dont be at yourself

I did the conservation of momentum experiment (m1v1 + m2v2 = (m1+m2)v3) for the Vectors experiment.

The paper was pretty good. Section A was a walk in the park, as were the short questions and Q12. Hopefully between my vectors, sound and Q11, I'm looking at a B2-A2.

Boston

Originally posted by ella minnow pea
dat was v v nice!
maths in it was so easy, and i got away with barely doing mechanics or electirity!

ITS OOOOOOOOVER!!!!!!!!!!!

I didnt do any mechanics and ony the simplest bit of electricty. The maths in the Cathode ray tube question was hard enough, they threw in afew tricks i'd seen befove, like puttign the magnetic force equal to centripedal force to work out the radius, and using the potential differnece definition to work out kinetic energy and then work out velocity. also if you amde a mistake you where ****ed for the whole what ever, 45 marks. Much easier options there.

teh bat was doing 10meter a sec, but i know some people got 9 come how

CuLT

So, who's up for some post LC sex0ring?

Zachary Taylor

I thought it was a pretty easy paper on balance. I hate physics and I really don't need it for points so I had left out the stuff I really couldn't stand like circular motion which cut down my options a bit. My only major problem is that Q11, which I usually like, was a bit chemistryish for my liking, and I had no idea how to use the periodic tables, but I'd say I got a good B, an A if im really lucky but I doubt it.

The bat thing was just c=f(lamda) I think. I can't remember what answer I got.

Anyway, I never have to do physics again!

Boston

Originally posted by Zachary Taylor
The bat thing was just c=f(lamda) I think. I can't remember what answer I got.

that was the speed of the radar wave, the next question was to find the distance, then you where asked the speed of the bat. nicely done to

eirebhoy

Originally posted by Bottle_of_Smoke
how fast was the bat travelling??????

I got 9.71 m/s. I don't know if i got it right, I took 70khz as the observed frequency and done the equation for observed frequency.

Dont be at yourself

I got the same answer, doing it the same way.

paniniter

you're all such big physics nerds

qwertyup

I thought it was an easy paper, compared to last years. This would be borne out by the fact that I managed to squeeze out an extra two questions in Section B, despite spending an hour and a half on Section A.

Unfortunately, I am getting worried that they are going to go postal on everyone with the marking scheme in response to the positive reaction. It may be overestimating the depths of evil in those civil servants minds, but it's still worrying me.

I think we should all mail off some letters bitching about the exam, just so that they don't think it is that easy.

Sev

Yeah, I got 9.71 too.

[nicK]

christ! what a paper to end the whole leaving cert on... i done terribly bad in that paper! pathethic!

my maths was terrible, i was looking far too deep into the questions and just got lost... i never would have excepted it to be so blatently easy therefore i was defeating myself even before i got to start every question and jumbled every piece of data up until it didnt make sence

i don't know what i done exactly in that exam, but i know i done bad.. just about scraped a pass i'd say, pathethic
my own fault, i'm pretty annoyed with myself after that display..

having said that, my leaving cert is over and after having done a surprisingly little amount of work, i seemed to have gotten throught it with reasonable good grades, although nothing to be proud of

iahh feck, let it be said, i'm pissed.. what in god's name have i spent the last 5mins writing about?

Boston

Originally posted by Scrappy]-[Nick
christ! what a paper to end the whole leaving cert on... i done terribly bad in that paper! pathethic!

my maths was terrible, i was looking far too deep into the questions and just got lost... i never would have excepted it to be so blatently easy therefore i was defeating myself even before i got to start every question and jumbled every piece of data up until it didnt make sence

i don't know what i done exactly in that exam, but i know i done bad.. just about scraped a pass i'd say, pathethic
my own fault, i'm pretty annoyed with myself after that display..

having said that, my leaving cert is over and after having done a surprisingly little amount of work, i seemed to have gotten throught it with reasonable good grades, although nothing to be proud of

iahh feck, let it be said, i'm pissed.. what in god's name have i spent the last 5mins writing about?

probably would have done better sleeping the night before instead of tryign to study the whole course. let that be a leasson to you.

Also The bat thing, i got 10 perfectly, but i used i slightly different forumla then is in the book(big stupid book) If didn't say leave your answer to one place of decimals so i'll still get full marks if its 9.7.

Boston

Originally posted by qwertyup
I thought it was an easy paper, compared to last years. This would be borne out by the fact that I managed to squeeze out an extra two questions in Section B, despite spending an hour and a half on Section A.

Unfortunately, I am getting worried that they are going to go postal on everyone with the marking scheme in response to the positive reaction. It may be overestimating the depths of evil in those civil servants minds, but it's still worrying me.

I think we should all mail off some letters bitching about the exam, just so that they don't think it is that easy.

Don't worry, there will be people up and down the country who falled it, like the repeat students i was sitting it with. Seriosuly what were girls thinking when they decided to do physics :rolleyes:

ella minnow pea

Originally posted by Boston
Seriosuly what were girls thinking when they decided to do physics :rolleyes:

1. I'm a girl
2. I got 9.71, like the rest of the world, so obviously you got that question wrong.
3. I thought all the maths in it were p!ss easy, like the rest of the girls in my class.
4. I'm going to get a higher grade than you.
5. Seriously what were ignorant boys thinking when they decided to do physics :rolleyes:

Boston

Originally posted by ella minnow pea
1. I'm a girl
2. I got 9.71, like the rest of the world, so obviously you got that question wrong.
3. I thought all the maths in it were p!ss easy, like the rest of the girls in my class.
4. I'm going to get a higher grade than you.
5. Seriously what were ignorant boys thinking when they decided to do physics :rolleyes:

Bit arrogant arn't you! the rest of the world didn't sit the physics exam love,

3) you didn't do all the questions and you yourself said you avoided the elctricity question where the more difficult maths where (the CRT mates ahd afew tricks but wasn't that hard once you copped it)

4) Yea well i'm pretty'er then you

5)I Decided to do physics for all the hot physics chicks :rolleyes:

ella minnow pea

yeah, i hate it when stupid people try to be funny :rolleyes: