[NoFunnyBusiness]

(Original post by kimmey)
can someone doing medical physics explain what and how an intensifying screen works for me

I didn't think we needed to know how they worked...

[kimmey]

(Original post by NoFunnyBusiness)
I didn't think we needed to know how they worked...

yeh im pretty sure we do haha, there's so much stuff to learn. do you know how to do the lens equation questions, if so can u help me i jus dont get them

[NoFunnyBusiness]

(Original post by kimmey)
yeh im pretty sure we do haha, there's so much stuff to learn. do you know how to do the lens equation questions, if so can u help me i jus dont get them

If you give me a question, I'll try, I sort of know (hate how there aren't as many past papers!). No guarantees though

Also re-applying for medicine this year! :P

[NoFunnyBusiness]

(Original post by kimmey)
yeh im pretty sure we do haha, there's so much stuff to learn. do you know how to do the lens equation questions, if so can u help me i jus dont get them

And something a little weird, got the same mark as you in Unit 4 physics :P

[desijut]

Time to start revising, yes... discovery of a nucleus mhm

[HadrianH]

Good luck to everybody taking this exam.

If anybody has material for Astrophysics, please send it my way!

Thanks

[sillehcaptcha]

(Original post by davey.gravey)
for people doing astrophysics section, I have the online textbook for the 3 chapters of cosmology, telescopes and surveying the stars. these cover everything, its basically an unprinted textbook for astrophysics (:

Anyone got any answers for the said "online textbook" *sigh* *facepalm*

Do not understand why the answers for AQA textbook answers are so hard to find...

[desijut]

After an hour and a half, i think radioactivity is quite nice rate of decay, properties, etc, will go over some more and do some questions before i move on

[R1Charles]

So just been checking what I need to revise with the Specification and was a bit confused to see we are expected to know the experimental verification of the inverse square law for gamma radiation.

Any ideas what sort of question they could ask on this? I'm guessing its to do with energy spreading out isotropically, over the surface of a sphere etc..?

[Insanity514]

Does anyone doing astrophysics actually feel confident with the 6 markers?
My teacher hasn't taught the points need to gain at least 4 marks in the 6 markers for the june 2010 and the june 2011 paper
Does anyone else feel like this or is it just my teacher?

[gukl]

Long shot but...Jan 03 PHA7/W (U5 option c) Question 4b?

calculate input power?

Given- Area enclosed by indicator diagram loop = 490J
Rotational speed of output shaft = 1800revmin-1
- 1 cyclinder

Mark scheme says: 1800/(60x2) = 15revs-1, work output each cycle = 380J?! (no idea where this comes from which loses me) so indicated power = 15 x 190 = 5700?

Completely lost agh!

EDIT: NEVERMIND ERROR IN THE QUESTION ACCORDING TO THE EXAMINERS REPORT. GAH.

[desijut]

(Original post by R1Charles)
So just been checking what I need to revise with the Specification and was a bit confused to see we are expected to know the experimental verification of the inverse square law for gamma radiation.

Any ideas what sort of question they could ask on this? I'm guessing its to do with energy spreading out isotropically, over the surface of a sphere etc..?

Was just doing this, it rings a bell. I think you use a GM (geiger-muller) tube and compare intensities at different distances and it should be such that I is proportional to 1/x^2

could be wrong but anyway, a 6 marker could be. Describe the experiment used to verify the inverse square law for gamma radiation, or something along those lines

[skibur]

(Original post by Insanity514)
Does anyone doing astrophysics actually feel confident with the 6 markers?
My teacher hasn't taught the points need to gain at least 4 marks in the 6 markers for the june 2010 and the june 2011 paper
Does anyone else feel like this or is it just my teacher?

Yeah, I agree, I think astro is on a whole quite a bit harder than the other section. I REALLY struggle with telescopes wahh

[Insanity514]

(Original post by skibur)
Yeah, I agree, I think astro is on a whole quite a bit harder than the other section. I REALLY struggle with telescopes wahh

I know telescopes

[skibur]

what are the grade boundaries like for this exam? I couldnt find them on AQA

[her17]

(Original post by insanity514)
i know telescopes

i hate telescopes

[Insanity514]

(Original post by her17)
i hate telescopes

What did telescopes ever do to you

Jokes aside yeh the **** me off but I went through them and now its not so bad.

[desijut]

(Original post by skibur)
what are the grade boundaries like for this exam? I couldnt find them on AQA

http://web.aqa.org.uk/UMS/index.php

Qualification: A2
Series: June10/11
Unit: GCE Physics 5A or 5B or 5C or 5D

5A=Astrophysics
5B=Medical Physics
5C=Applied Physics
5D=Turning Points in Physics

[gimboid]

anyone got or know where the specimen is?

[Machoo]

I'm really struggling with Astrophysics. It's the only thing that's letting me down really. I haven't done Chemistry for a long time, and I was exactly very good at it, so Absorption lines aren't a speciality of mine.

Anyone have any idea where I could fine some good revision notes on Absorption lines which is up to the standard of A2 work, without actually purchasing a Chemistry text book?

How's everyone finding the rest of Astrophysics?