[jlnbello]

is the threshold of hearing in the formula book in unit 5 physics?

[internet tough guy]

Calling all astrophysics option-takers, do we need to know how to derive the equation on the formulae book?

for example, the lens equation? - I'd hate to have to derive that, always a mind**** with geometry

[TheRenaissanceMan]

(Original post by internet tough guy)
Calling all astrophysics option-takers, do we need to know how to derive the equation on the formulae book?

for example, the lens equation? - I'd hate to have to derive that, always a mind**** with geometry

For Astrophysics no deriving of equations.

[robthefool]

(Original post by Amirrryy)
can someone tell me whether i would be able to revise turning points and do the papers in one day? (i.e. tomorrow?) i am planning on getting up at like 7. did section A and finished all papers from old and new spec. i am planning on revising the stuff first and then doing papers. any advice on how i could save time would be appreciated.

Probably mate. I'm doing an all nighter right now learning the astrophysics and it's coming along nicely.

My plans were screwed when AQA decided to make unit 4 a b****, I was counting on only needing to get about 50UMS on this, but now I am going to revise this like crazy, going to uni depends on this!

Most of it is sinking into my head. I'm going to go over the topics again tomorrow untill about 3pm and then do past papers. I'm actually finding radiation the hardest atm

[internet tough guy]

(Original post by TheRenaissanceMan)
For Astrophysics no deriving of equations.

Thank ****!, what about for the nuclear and heat/gas parts, do I need to know how to derive any of equations?

[Xarren]

(Original post by Amirrryy)
can someone tell me whether i would be able to revise turning points and do the papers in one day? (i.e. tomorrow?) i am planning on getting up at like 7. did section A and finished all papers from old and new spec. i am planning on revising the stuff first and then doing papers. any advice on how i could save time would be appreciated.

Thats what I'm doing.

[Khhbartonch]

(Original post by robthefool)
Probably mate. I'm doing an all nighter right now learning the astrophysics and it's coming along nicely.

My plans were screwed when AQA decided to make unit 4 a b****, I was counting on only needing to get about 50UMS on this, but now I am going to revise this like crazy, going to uni depends on this!

Most of it is sinking into my head. I'm going to go over the topics again tomorrow untill about 3pm and then do past papers. I'm actually finding radiation the hardest atm

me too! all the past questions are so confusing because its a small topic they decide to make all the questions on it ridiculous

[laughingbagel]

For those taking astrophysics, can anyone explain why the relative abundance of H and He is a supporting argument for the Big Bang Theory?

[kimmey]

anyone got any ideas what the 6 marker could be ?

[tuckaa]

(Original post by laughingbagel)
For those taking astrophysics, can anyone explain why the relative abundance of H and He is a supporting argument for the Big Bang Theory?

From what ive gathered from essentially learning this topic by myself from like 4 resources.. (just saying in case ive gathered it wrong, if someone can tell ive got it wrong please let me know!)

Basically the big bang theory predicted that after the big bang, when the universe was still very young there was a brief period of hydrogen fusion. This would have lead to there being a radio of 3 hydrogens to 1 helium in the universe. As we can measure the ratio at different places in the universe and we get this 3:1 ratio everywhere, it supports the theory.

[thenumber2goose]

(Original post by kimmey)
anyone got any ideas what the 6 marker could be ?

I reckon maybe something on the safety features of a power plant or possibly why Technecium-99m is used in medicine.

That's what i'm hoping for anyways.

Saying that in Jun10 it was from the nuclear energy section and in Jun11 it was from the thermal physics section. So by logic, it could be something from the radioactivity section

[tuckaa]

Can anyone explain to me electron degeneracy pressure (And neutron as well) or do we not need to know how it works just that its there /what effect it has?

[thenumber2goose]

(Original post by laughingbagel)
For those taking astrophysics, can anyone explain why the relative abundance of H and He is a supporting argument for the Big Bang Theory?

If you imagine the big bang, the explosion itself would only last a matter of nanoseconds. During this explosion, the conditions would obviously be incredibly hot. This would not be long lasting, as the explosion continued to spread out, so would the heat. The idea is that during the initial nanoseconds of the explosion, it was hot enough for Hydrogen to fuse forming helium. However, as these hot conditions were so short lived, larger nuclei were unable to be formed. So, as the explosion continued to spread out, the hydrogen and newly formed helium spread out with it resulting in a ratio of 3:1 spread uniformly throughout the universe. That's my take on it anyway.

[Hulksmash]

(Original post by leeandrewarmstrong)
Any predictions for the 6 marker in Radioactivity/Thermal?
I hate those 6 markers!

I think it may be a radioactivity/nuclear question rather then thermal physics

[thenumber2goose]

(Original post by Hulksmash)
I think it may be a radioactivity/nuclear question rather then thermal physics

Yeah me too after thinking about it because it was a Thermal one last year, but you never know with AQA. As I said in a recent post, I think it could be something on the safety features of a power plant or possibly why Technecium-99m is used in medicine.

[TheRenaissanceMan]

(Original post by internet tough guy)
Thank ****!, what about for the nuclear and heat/gas parts, do I need to know how to derive any of equations?

You need to know how to Derive the Kinetic Molecular Gas equation, the one where you have a particle in a Box. That's the only thing you need to derive (and you can confirm this in the spec)

[Hulksmash]

[QUOTE=leeandrewarmstrong;3816355 5]Yeah me too after thinking about it because it was a Thermal one last year, but you never know with AQA. As I said in a recent post, I think it could be something on the safety features of a power plant or possibly why Technecium-99m is used in medicine.[/QUOTE

Or to describe an experiment about radioactivity or the inverse square law of gamma radiation.

[thenumber2goose]

[QUOTE=Hulksmash;38163593]

(Original post by leeandrewarmstrong)
Yeah me too after thinking about it because it was a Thermal one last year, but you never know with AQA. As I said in a recent post, I think it could be something on the safety features of a power plant or possibly why Technecium-99m is used in medicine.[/QUOTE

Or to describe an experiment about radioactivity or the inverse square law of gamma radiation.

Oh yeah, hadn't thought of that. I shall be revising that today! :L

[thenumber2goose]

In case some of you didn't see them yesterday here are my Thermal/Nuclear key points and my astrophysics notes. Hopefully they may be of some use

[internet tough guy]

Guys, for nuclear fission, the mass of the original nucleus is smaller than the combined mass of the constituent nucleons that it splits into. Whereas for nuclear fusion, the combined mass of the constituent nucleons is less than what the mass becomes when they fuse into one nucleus.

Is that all correct? So 'Before' mass is always less than 'After' mass?