Physics->?

Naikon

Quick question, If you are not looking for an A1, is it possible to leave out a
particular section of the course?

I am thinking of leaving out mechanics(minus experiments) and some Optics(fecking ray diagrams:mad:)

I intend to do Electricity as I dont have to much trouble with that entire section(which is odd considering most people hate it)in
comparison to the Atomic physics which throws me off a little.

I think I might do applied Electricity, as even though it is longer, the stuff on bi-polar transistors as switch/amplifier and Logic gates are handy if they came up in the exam.

What do you think:D

If you're not looking for the highest marks, of course it's possible to leave out a section! Or did I not get the question?

The one problem (which I've found in my college exams) is having 'banking questions'. These are the questions that come up every year, or should come up every year.

I don't wish to jinx you, but you might be the year that they decide to put a huge emphasis on Mechanics. Or Optics. Or whatever!

JC 2K3

I never understood people finding mechanics hard, then again I hate electricity, so different strokes....

And you can indeed leave out a sectin or two if you don't want very high marks.

ninebeanrows

Well Mod Science will seemingly always get you 1Q, maybe even another half. and Particle Physics will always get you 1Q. Electricity will get you 1 and a half. Mechanics will get you 1Q and half.

You could certainly leave out Light but that stuff is easy. It would seem from my study of the papers they seem to throw up 1 full Q on the lesser sections as in the ones that i have not mentioned and then maybe 1 bit or 2 in the bits question.

Q5 is always a random selection though.

And the experiments always have 1 Electricity and 1 Mechanics.

I do more studying of the papers than anything else:o

sd123

See i feel really bad now because i am aiming for an A and completely leaving out electricity ( the worst part of the course in my opinion ). By the way P=IV seems to contradict V=IR in my opinion. one says that v is proportional to Current and the other says that it is inversely proportional. Sorry to get off the point but yea by all means leave out a topic or two.:rolleyes:

Tomlowe

That's always confused me slightly as well, I think ohms law is for a voltage drop and P=VI is for potential difference... but i dont really understand that at all

JC 2K3

sd123 wrote:

See i feel really bad now because i am aiming for an A and completely leaving out electricity ( the worst part of the course in my opinion ). By the way P=IV seems to contradict V=IR in my opinion. one says that v is proportional to Current and the other says that it is inversely proportional. Sorry to get off the point but yea by all means leave out a topic or two.:rolleyes:

The V in V=IR is the voltage across a line, the "voltage drop", or simly "the voltage difference from one end to another". The higher the voltage drop the more energy converted to heat and therefore lost.

The V in P=IV, however, is the voltage on the line. The P in this case is the power you want to transfer from one point to another.

If you use the voltage across the line in P=IV you get the power/heat loss, I like to write this as Ploss=IV, or Ploss=I^2R.

So lets say you want to transfer a certain power, P, from A to B. The Ploss is diretly proportional to I, so you want I to be as low as possible. The P is directly proportional to the voltage on the line and I and it is a constant value(since you want to transfer a certain amount of power). Therefore the higher V across the line is the lower I will be and the lower the power loss will be.


My teacher didn't explain this to me well either, I had to research it myself, but when you grasp it it's fine.

RandolphEsq

Good work JC

eZe^

This may be handy for some people. Lately Ive just been watching one of these lectures a day, good revision and whatnot for the leaving, saves me the whole writing stuff down!

http://ocw.mit.edu/OcwWeb/Physics/8-02Electricity-and-MagnetismSpring2002/VideoLectures/index.htm

dan719

Mit Open courseware.Good Idea. Glad to see I'm not the only one using it. The nuclear engineering materials are particularly interesting, but probably of little or no use to you in the physics exam in june. Still cool

cookiemonst3r

sd123 wrote:

See i feel really bad now because i am aiming for an A and completely leaving out electricity ( the worst part of the course in my opinion )

I asked my teacher if i could leave out electricity and she told me ya if i wanted to get a C or D. so maybe leavin it out isnt the best thing

sd123

i asked my teacher the same and she said that she wouldn't recommend it because although it probably wouldn't happen, theres nothing to say that 2 electricity Q'S wont come up in the experiments cos theres no set rule for it.

cookiemonst3r

O really :eek: well thats great. I doubt they'd do that though. I hope they don't!

dan719

But unofficially do they not always examine one experiment form each of the four key sections. Not only that but the electricity exp. are very easy and similar, it would be like asking the same question twice!

cookiemonst3r

ya every year the exps are from different areas. But you never know this could be the one year that they change it! I'm so paranoid about them changing things on the paper.

dan719

But we cannot legislate for that so no point in worrying about it! you can only answer the test they give you.

sd123

The other thing is that they're raging cos not enough people are doing phy so they're trying to make the exam easier but you'll never know what they'll do.

cookiemonst3r

ya nd apparently theyre going to cut out some of the stuff on the course cos they think its too long! I think physics has a short enough course as it is.

JC 2K3

Physics is the shortest course I do bar App Maths. I could revise the whole course in a week....

Donald-Duck

You can easily leave electricity or mechanics out and get an A. However, learn the god damn mandatory experiments for them sections. It takes 5minutes to learn an experiment so its not worth taking the risk in section A

nick23

You can easily leave out one topic and still get an A (im leaving out electricity for example!) but i'd try and get a basic knowledge of some of the more fundamental elements of each section. That way you're covered for Q5 and if you're really stuck you can always give one of the questions you dont know too well a go

Naikon

Thanks for the speedy responses.
Yeah I will probably leave out Mechanics as I find Electricity isnt too bad.

I am considering the applied Electricity as even though its longer, I think its a more interesting and relevant to my life in comparison to Particle Physics which is a little more predictable but....Boring:D
But hey thats just me:)
I am going to go over those section A experiments very well, as you all know its a good 30% foundation to build on.

Naikon

JC 2K3 wrote:

Physics is the shortest course I do bar App Maths. I could revise the whole course in a week....

Fair play:eek:
That big black folens book is full of stuff that probably wont be on an LC exam so I believe you.
I think the trick really is in the exam papers a this stage.

JC 2K3

Not really...

Monday: Optics
Tuesday: Mechanics
Wednesday: Heat + Light/Sound waves
Thursday: Electricity
Friday: Magnetism
Saturday: Electron/Radioactivity/Particle Physics
Sunday: Spare day cos you mightn't get each of those topics covered in one night.

Remember mechanics comes into a lot of other questions, especially ones involving the movement of an electron. Know the main formulae anyway.

Naikon

Hmmm, thats sounds manageable Considering the Physics course is indeed alot shorter than most.
So just doing exam papers from now on in using notes as a study reference is advisable?
Thanks for reminding me about how mechanics can pop out in other areas, I know the basics of Mechanics its just Circular motion etc I should probably....study:)

JC 2K3

Ek = (mv^2)/2 is used quite frequently also outside the mechanics question.

Gangsta

I think JC 2K3 should write a concise revision book

Nehpets

and then he should eat it

JC 2K3

I should, I really should.....

I'm working on something kinda like that. You guys'll see in a week or two, not necessarily just for physics, but, you'll see....

sd123

yea i'd love a copy of that!

Tomlowe

I heard today that I'm going to have to produce an experiments book or else not sit the exam... balls

ninebeanrows

Tomlowe wrote:

I heard today that I'm going to have to produce an experiments book or else not sit the exam... balls

herrrrhar stinger, hope i dont arve to or else i'll have to get writing

sd123

one thing should be said if leaving out a topic.
DONT LEAVE OUT STATIC ELECTRICITY ( IE COULOUMBS LAW ETC.) ALTHOUGH UNBELIEVABLY BOOOOOORING SOME OF THE QUESTIONS IN THE LAST FEW YEARS HAVE BEEN AMAZINGLY EASY

apparantly barely no one does this question cos its really un interesting but once you know the definitions and the formula its pretty easy to get almost full marks!:D

ethernet

sd123 wrote:

one thing should be said if leaving out a topic.
DONT LEAVE OUT STATIC ELECTRICITY ( IE COULOUMBS LAW ETC.) ALTHOUGH UNBELIEVABLY BOOOOOORING SOME OF THE QUESTIONS IN THE LAST FEW YEARS HAVE BEEN AMAZINGLY EASY

apparantly barely no one does this question cos its really un interesting but once you know the definitions and the formula its pretty easy to get almost full marks!:D

It's not the worst question, in fairness. There question seems to be rather similar each time it appears too.

ninebeanrows

Yes i'm beginning to question Electricty..

If i do Modern Science and Particle Science = 2.5 Q's

If i do Mechanics = 1.5 Q's

and then do all thos easier chapters = at least 1 Q

The theoretically i can leave out Electricty?

mmmmmm interesting

fuinneamh

JC 2K3 wrote:

Physics is the shortest course I do bar App Maths. I could revise the whole course in a week....

have revision notes that amount to 9-10 A4 pages of main body of course and then summarised versions of the experiments in mainly diagram form. enables me to do a good revision of the physics course in around 2 hours, though i must say economics is shorter at an amazing 8 A4 pages.

Gangsta

I've a question for all ye physics nerds...mainly looking at JC 2K3

How does dispersion occur on a CD?

Also don't just copy and paste the book's explaination, I haven't a clue what it's talking about!

JC 2K3

CDs are made up of minute indents of different levels depending on the data and when white light falls on the light waves are reflected back at different angles. As white light is made up of light waves of many different wavelengths(ie. colours), the colours are dispersed.

cocoa

Possibly you meant it to be understood but isn't dispersion on a CD very similar to that of a diffraction grating? only, hypothetically, one with a mirror behind it. Light hits tiny indent, is reflected back out through tiny gap=>diffraction=>interference pattern=>colours
that's what I thought anyway....