Physics

Africa

Well, there is LOADSon the course...so what are you studying for the LC? Any tips?

Gone West

how did you do in the mock? I did v badly. i also need tips!

*Angel*

I'd say make sure you know all definitions and experiments (easy marks) even though I hate going over experiments. If you're refining yourself to certain topics make sure you understand what you're learning, one thing about physics is you must understand the stuff if you're going for a high grade.

I'm doing most stuff: mechanics, optics, heat, waves, electricity (& magnetism/heat). I don't really like the electricity option q so I'll probably won't bother with it (those damn diagrams), I haven't studied particle physics yet but I think it would be a good question in the exam.

mickomack

If you haven't studied up till now(I know the feeling) and you feel that you know nothing the best place to start is learning the experiments these account for 30% of the marks,Definitions only account for 10% so they are not exactly a huge factor. Particle physics is far easier than the app electricity section and sice the app elect. is the more popular q it tends to be that bit harder of a question.
There are only about 3 formulae in particle physics and the chapter is shorter in comparison to applied electricity

angeldelight

As previously said, make sure you learn all the experiments. Definitions and formulae are the next thing. As for what area of the course I'd say def study mechanics and particle physics! It's not that bad a subject if you know those things.

dudara

go to the examinations website, and get yourself copies of the past papers and the marking schemes. These will show you what the examiners are told to give marks for. Remember, it's not enough to learn a formula. You must be able to state what physical quantity each variable represents.

Also on the dept of education website, you can get copies of the syllabus and a teachers physics manual, which is basically another textbook. Useful to have, in case it explains a topic in a better fashion.

JackKelly

past papars. Applies to every subject, but keep doing questions.

*Angel*

TimAy wrote:

past papars. Applies to every subject, but keep doing questions.

I really would focus more on just knowing the stuff, rather than relying on the past papers, the course is newish so there isn't too much repitition going on.

4Xcut

Africa wrote:

Well, there is LOADSon the course...so what are you studying for the LC? Any tips?

what are you on about? it is shorter than any other science course, and one of the shortest courses on the leaving cert. Are you learning the book by heart or something stupid

Gone West

yuo actually need to know the book really well, because some damn obscure questions can come up.

D-Generate

Don't just use the book. Download the syllabus off the internet and use that and referance to the book. The books have loads of information you don't need and sometimes lack information you do need. Remember at the end of the day the questions from from the syllabus, not from a physics book.

*Angel*

What books do you guys have, I have the Physics Today one and it is absolutely sh!te, yeah syllabus is well worth noting, I have it printed off and I use it as a revision list kinda thing.

Africa

Ah you do. I have the OPhysics now book, about 300 a4 pages long if not more. I have notes done out myself but you do need to know a lot of detail which is really annoying...

dudara

*Angel* wrote:

I really would focus more on just knowing the stuff, rather than relying on the past papers, the course is newish so there isn't too much repitition going on.

yey and nay. if you read the marking schemes, you get an idea of how to answer questions, rather than the knowledge itself. You learn how the marks break down, so you can get good at figuring out how many points they want in the answer etc.

also, you just begin to develop a good answering style, which will always encourage the examiner to think favourably of you

in the end of the day, there's no escaping the fact that you will have to know the stuff too

breadmonkey

As well as learning the Section A, go through the book and make a list of all the "demonstration" experiments, then decide which ones are worth learning. There are always questions like "describe an experiment to measure....".

Mechanics is a piece of p!ss if you're doing applied maths.

Particle physics is easy too.

Learn all the required proofs. If one comes up you'll be laughing.

Physics is very easy IMO, they give you tons of marks for just slotting values into a formula.

*Angel*

breadmonkey wrote:

"demonstration" experiments

I HATE them! I always forget them...

breadmonkey wrote:

Mechanics is a piece of p!ss if you're doing applied maths.

Yeah v. easy, handy

breadmonkey wrote:

Particle physics is easy too.

Yeah are stupid sh!te teacher only started it last class, but it's sure to help me improve from the mocks.

sephirosis

this year is a celebratory year for einstein's equation on the photoelectric effect, so a question on it will probably appear somewhere, be it Q9, 11 or 12. Also the photocell which is realted but hasn't appeared on a paper since the new course. good luck

*Angel*

The pendulum is looking pretty likely aswell.

ApeXaviour

TimAy wrote:

past papars. Applies to every subject, but keep doing questions.

I'll second this and say it applies especially to physics. I give grinds in LC physics and I cannot tell this enough to my students. There are a rakeload of sample papers pseudo-pre-2002 ones that have tons of relevent questions if you run out (and you should) of actual past questions.

Have your book beside you. If you cant do the question, open your book and look up / learn what you need. Then close it (also turn your notes over) and try to do the question again completely from your head. At this stage it is the best way to learn..


An extra tip: A few days before the exam practice out all the derivations (6 I think), once looking at them in the book, the next on your own. There's not a whole lot of point learning them all off until right before the exam so they're fresh in your memory and you can regurgitate them quickly at will.

CoffeeFreak

An extra tip: A few days before the exam practice out all the derivations (6 I think), once looking at them in the book, the next on your own. There's not a whole lot of point learning them all off until right before the exam so they're fresh in your memory and you can regurgitate them quickly at will.

Hey, do you have a copy of the long derivation (I think it's from the electromagnetism chapter), because our teacher did a really short version of it and my friend who goes to the institute said it's not accepted...I can't find it anywhere.

Waltons

I'm thinking that Snell's Law or the refractive index of a liquid could come up in Section A. I wouldn't be surprised if Joule's Law came up either.
As already said it's an anniversary for the photoelectric effect as well, so there's a good chance that'll come up. E=mc^2 is usually a good backer as well. I'm going to give Particle Physics a bash myself too seeing as it's definitely going to come up and it's mostly learning off facts rather than the ability to do sums

*Angel*

CoffeeFreak wrote:

Hey, do you have a copy of the long derivation (I think it's from the electromagnetism chapter), because our teacher did a really short version of it and my friend who goes to the institute said it's not accepted...I can't find it anywhere.

Does your friend from the institute not have it?!?!

Anway I'm pretty sure this is all you need to have:

Force on a charged particle

A stream of charged particles each carrying a charge of q and moving at a speed of v, through a distance L, and taking a time of t to do so.
Distance = speed x time, therefore L = vt
Current = charge/time, therefore I = q/t
The force on a current-carrying conductor in a magnetic field is given by F = BIL
A stream of electrons constitutes a current, so
F = BIL = B(q/t)(vt) = Bqv

CoffeeFreak

*Angel* wrote:

Does your friend from the institute not have it?!?!

Anway I'm pretty sure this is all you need to have:

Force on a charged particle

A stream of charged particles each carrying a charge of q and moving at a speed of v, through a distance L, and taking a time of t to do so.
Distance = speed x time, therefore L = vt
Current = charge/time, therefore I = q/t
The force on a current-carrying conductor in a magnetic field is given by F = BIL
A stream of electrons constitutes a current, so
F = BIL = B(q/t)(vt) = Bqv

Thanks, that's the one we did, and the institute teacher said it wasn't right! Apparently there's a really long version. Yeah, I did ask my institute friend for it but she never gave it to me .

*Angel*

CoffeeFreak wrote:

Thank you! Yeah, I did ask my institute friend for it but she never gave it to me .

No problem!

ApeXaviour

CoffeeFreak wrote:

Thanks, that's the one we did, and the institute teacher said it wasn't right! Apparently there's a really long version.

Heheh if the institute teacher is Pat Doyle (best teacher I've ever known by the way) then that's fairly typical. He really hates "woolly" explanations to things. The above short derivation is only kinda right yet will probably be accepted by the LC markers (though I'm not entirely sure). I've written the longer, more physically correct derivation below:

Say you have a wire of cross-sectional area A and length L that contains particles, each with charge q and drift velocity v. And we define t as the time taken for a charge to travel the length L, such that vt=L.
N - the total number of charged particles in the wire.
n - charged particles per unit volume such that n=N/AL
nq - total charge per unit volume
nqvtA - total charge in wire, since L=vt
Since current is defined as total charge travelling the length of the wire divided by time t then:
I = nqvA
Force on a charge carrying conductor is: F=BIL
Therefore:
F=BnqvAL - force on all charged particles in wire
But since n=N/AL then:
F=BNqv
If this is the force on all charged particles in the wire then the force on one charged particle is f=F/N
Therefore: f=Bqv

If you want me to elaborate on any bits that don't quite click, let me know. It's no problem, really. If you understand it through you'll see its a pretty kewl and remarkable derivation..

David19

Apex did you go to the institute? Or were you there for revision classes? Im a former student of Pat Doyle myself.

ApeXaviour

I was there for Saturday classes, my own physics teacher being unaware of such things as anti-matter. This was back in the 01/02 academic year though..

David19

Haha fair enough. I went there for 6th year in 02/03. He's a good teacher alright.

D-Generate

Section A
Mechanics: Conservation of Momentum or F α a

Heat: Doubt Heat will come up this year but if it does it will be S.H.C of a liquid.

Electricity: Thermistor or else resistance of wire with temperature. All other heat ones have been asked recently and the IV of diode in forward/reverse bias is unlikely to be asked because many schools have difficulty producing results for it in a lab. They could bump thermistor in to the Heat question or vice-a-versa.

Waves: Speed of Sound in Air

There has yet to be a curve graph asked so this year will be it methinks or so my teacher tells me. So make sure you know your curves. There is a possibility of the pendulum appearing but last year tehy did g by free fall and got in to hot water for specifying a method of measuring g when there are 3 at least.
They will probably not ask for calibration curve of thermometer because they never specified a thermometer we have to calibrate and there are 4. Also its very hard to get 50 marks out of that question.

Section A is piss anyway, do the two graphs and one other basically. Easy marks in my opinion.

Section B my first choices will probably be,
Question 5 - Choice
Question 12 - Choice
Question 11 - Difficult to lose many marks in.
Question 10 - Option is piss easy
Then I will do Electricity because I looooove Electricity or Mechanics because its grand if you do Applied Maths.
The Modern Physics question has nice maths in it too which is easy.

Wheatstone bridge will come up this year too folks, came up in the revised smaple paper and has yet to be asked and not much left in electricity they can ask.

ApeXaviour

It's not a good idea to attempt to predict LC exams.. Take it from those who have done them. Truly if you think you see a pattern, you are wrong, the questions are almost picked at random.


Quote from everybody (new) english exam 2002. "Heaney is sure thing!". Left a lot of people in a lot of trouble doing their poetry.. Similar but less drastic failures of clairvoyance also happened in the physics exam of that year..

rainbow kirby

Lol, I said 'Eavan Boland is a sure thing' that year. I was right.