June 2011 G485-Fields, Particles and Frontiers of Physics

Giving it till 9 then im starting reading over my revision guide again, then once again in the morning. I feel like i cant take anymore physics in.

Reply 701

ChoYunEL

1

Original post by susan23

giv me the page its on.

In the Physics 2 for OCR book, page 265
It's not in the OCR Physics A2 book...

Reply 702

muffingg

18

Original post by susan23

giv me the page its on.

I don't know which one you have. Mine is by Gurindher Chadha and it has some stars or something on the front cover. Page 265:

"A white dwarf is prevented from further gravitational collapse by electron degeneracy pressure (also known as Fermi Pressure). This comes about as follows. There is a law called Pauli's exclusion principle which states that no two electrons can exist in the same quantum state. (This is why only two electrons can occupy any energy level in an atom.) As gravity tries to cause the star to collapse further, a limit is reached when further collapse would require two or more electrons to exist in the same quantum state."

Reply 703

ChoYunEL

1

I'm getting lost in space. Because it's so isotropic.
eheheheheh

Reply 704

jam.wa

8

Original post by ChoYunEL

I'm getting lost in space. Because it's so isotropic.
eheheheheh

I just love the word 'homogeneous', it's a great word.

Reply 705

trapzbrah

9

Original post by ChoYunEL

I'm getting lost in space. Because it's so isotropic.
eheheheheh

Reply 706

jam.wa

8

Original post by muffingg

And it's infinite. :smile:

Spoiler

Try telling that to Olbers

Reply 707

CoffeeStinks

11

Original post by Rosieretops

I would like to know this too. It's nearly impossible to remember, I think you would get most marks for getting it in the right order. They like it when you show a clear sequence of events.

I hope just explaining it will suffice since it only says Describe the evolution. It doesn't mention quantitatively so hopefully they don't need figures. If they do I've lost the marks because I haven't got time to learn them.

Reply 708

muffingg

18

Original post by jam.wa

Try telling that to Olbers

Ah sh;t. Fail! It's not infinite. But anyway Olbers would have agreed with it.

Reply 709

trapzbrah

9

Original post by muffingg

Ah sh;t. Fail! It's not infinite. But anyway Olbers would have agreed with it.

you sound like you're ready?

Reply 710

ChoYunEL

1

Original post by muffingg

Ah sh;t. Fail! It's not infinite. But anyway Olbers would have agreed with it.

Yeah, it's Isotropic and homogeneous ;P
But I couldn't really say I get lost because of homogeneous... I suppose..

Reply 711

jam.wa

8

Original post by muffingg

Ah sh;t. Fail! It's not infinite. But anyway Olbers would have agreed with it.

Something most people don't know about Olbers; he invented an oil that clears blocked noses...

WHAT A GUY!

Reply 712

Beth1234

11

Hello!

Could someone help me with the following question:
The star Tau Ceti has a parallax of 0.275 seconds of arc.
Calculate the distance of Tau Ceti from Earth in parsec (pc).

Most of you probably recognise it from as 5.b.i) from the Jan 2011 paper. I have of course got the mark scheme...but can't seem to follow what they're doing...

I suspect it's really obvious, and that I'm just having a brain freeze after five hours of exams today :rolleyes:

Reply 713

muffingg

18

Original post by trapzbrah

you sound like you're ready?

In some areas I'm more than ready whereas in others I don't know the ABC of it.

Reply 714

Rosieretops

Original post by CoffeeStinks

I hope just explaining it will suffice since it only says Describe the evolution. It doesn't mention quantitatively so hopefully they don't need figures. If they do I've lost the marks because I haven't got time to learn them.

I have the OCR checklist and it does say you need to know it qualitatively unfortunately and I wouldn't put it past them to ask horrible questions like that because they love it.

Reply 715

XST

Original post by Beth1234

Hello!

Could someone help me with the following question:
The star Tau Ceti has a parallax of 0.275 seconds of arc.
Calculate the distance of Tau Ceti from Earth in parsec (pc).

Most of you probably recognise it from as 5.b.i) from the Jan 2011 paper. I have of course got the mark scheme...but can't seem to follow what they're doing...

I suspect it's really obvious, and that I'm just having a brain freeze after five hours of exams today :rolleyes:

Number of parsecs is inversely proportional to the angle of parallax, so as angle decreases, number of parsecs increases.

Divide the 1 parsec by the angle of parallax 0.275 and you get 3.64 parsecs.

Reply 716

Oh my Ms. Coffey

Ask me more questions.

Reply 717

ChoYunEL

1

Original post by Oh my Ms. Coffey

Ask me more questions.

18. Physicists are attempting to find a unified theory of the fundamental forces of nature.
(a) Name the four forces involved.
[4]

(b) State the force involved in:
(i) holding quarks together in a proton.
[1]

(ii) decay of a proton.
[1]

(iii) particle scattering by a nucleus.
[1]

(c) These forces are described by the exchange of particles. Name two of the exchange particles
involved in the situations listed in b).
[2] (These questions are from the old spec, I don't think we need to know about exchange particles.)

(edited 12 years ago)

Reply 718

Kalamari Dave

Original post by Oh my Ms. Coffey

Ask me more questions.

What equations should we know for tomorrow?
What constants should we know that aren't in the formula book (e.g. Parsec in km)?
How much of the spec would you say could come up as wordy questions?
How much have you revised?
What's your offer requiring your physics grade to be?
How many marks do you need in this module to walk away with that grade?

Reply 719

Oh my Ms. Coffey

Original post by ChoYunEL

18. Physicists are attempting to find a unified theory of the fundamental forces of nature.
(a) Name the four forces involved.
[4]

Gravitational force
Electrostatic force
Weak Nuclear force
Strong Nuclear force
(b) State the force involved in:
(i) holding quarks together in a proton.
[1]
Strong Nuclear force
(ii) decay of a proton.
[1]
Weak Nuclear force allowing Quark flavours to change in Beta plus decay

(iii) particle scattering by a nucleus.
[1]
Electrostatic?
(c) These forces are described by the exchange of particles. Name two of the exchange particles
involved in the situations listed in b).
[2]

Beta plus decay proton -> Neutron + Positron and a Neutrino

June 2011 G485-Fields, Particles and Frontiers of Physics

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you