AQA Physics PHYA5 - 28th June 2016 [Exam Discussion Thread]

Just going over all the topics before I crack on with past papers, I love the fact that there are no other papers scheduled around this paper, I can just focus on just physics!!

Can someone answer me why for electron scattering we use lambda=hc/E to determine wavelength rather than de broglie equation? I would have thought as its and electron we would have to use Lambda=h/mv, or are they the same thing but rearranged somehow?

Oh and am I right in thinking the reason electrons need to be fast enough for relativistic phenomena to come into play is because they only display wave like properties at this speed?

Thanks for any help!

Wish I could just focus on Physics; FP3 and S2 both Monday morning.

Reply 241

ABoyHasNoName

2

Anyone got a KEY WORDS document?

Reply 242

Seclusion

2

What 6 marker could they ask for astro this year?
I'm guessing something about Wien's law/Stefan's law, considering they have never asked about that?

Reply 243

philo-jitsu

2

Original post by cjlh

Wish I could just focus on Physics; FP3 and S2 both Monday morning.

damn dude, I was moaning about messing up core 4 because I had 4 exams last week, I should shut up lol

good luck mate

Reply 244

MintyMilk

3

Original post by philo-jitsu

I love the fact that there are no other papers scheduled around this paper, I can just focus on just physics!!

FP2 is the day before it

Reply 245

cowie

7

Anyone else dreading the six markers?:/

Posted from TSR Mobile

Medical predictions?

Original post by Seclusion

What 6 marker could they ask for astro this year?
I'm guessing something about Wien's law/Stefan's law, considering they have never asked about that?

What 6 marker could they ask for Wien's and Stefan's law?

Reply 248

treeporn

For those doing the Turning Points module, could someone tell me whether the the proper value of time dilation t0 is in the moving or rest frame? From my research (which is contradicting the mark schemes) I've been going by the fact that 't' is the proper time in the rest frame and 't0' is the time in the moving frame because the time dilated in the moving frame is greater?

So I've paired up L0 (length is always greatest in the rest frame) with t in the rest frame and L with t0 in the moving frame but the mark schemes indicate that L0 is paired up with t0 meaning time dilated is greatest in the rest frame so I'm dead confused.

I kind of get the concepts but I look at these questions more from ratio point of view so if anyone could clear up my confusion i'd be grateful.

Reply 249

idk97

1

Original post by ChillGod

Look in the unit 4 park of the formula sheet - electric fields. W=QV.

It's the same just different symbols. Work done and energy is the same. Remember energy is defined as the ability to do work. V is the potential difference. e is the charge, Q.

Formula just changed to fit electrons in a field.

omg i feel silly. thank you

Reply 250

beggelton

(for part A, that everyone does) Do we need to specifically know about argon dating? It's not in the CGP book and i don't rate the Nelson whats-it book, load of shite if you ask me. Any thoughts? :smile:

Reply 251

CJRobson98

Original post by Mango Milkshake

I agree, and the boundaries are really high because less people do each module.

If anyone is asking a question about an optional unit can you please state which unit as to not confuse others. Thanks

You madame, are wrong.

Reply 252

particlestudent

13

Original post by beggelton

(for part A, that everyone does) Do we need to specifically know about argon dating? It's not in the CGP book and i don't rate the Nelson whats-it book, load of shite if you ask me. Any thoughts? :smile:

Yes it says in the spec. I've came across one question so far on the radioactivity question pack on physicsandmathstutor.com on argon dating. But they did tell you about the ratio in the question.

Reply 253

C0balt

16

Original post by cowie

Anyone else dreading the six markers?:/

Posted from TSR Mobile

Oh man not only do i dislike six markers but we've got two coming up! :puke:

Reply 254

MintyMilk

3

Original post by C0balt

Oh man not only do i dislike six markers but we've got two coming up! :puke:

Design an experiment using classroom apparatus to determine the age of the Universe

Astro life is hard

Reply 255

zjkdnnn

1

Hi

for estimating the nuclear size using electron diffraction what causes the first minima?

Reply 256

cowie

7

Original post by zjkdnnn

Hi

for estimating the nuclear size using electron diffraction what causes the first minima?

Think back to diffraction grating at AS Physics. So: d sin (theta) = n(lambda). It's the first minima you're talking about so discard n as it = 1. This gives you d sin(theta) = lambda. Rearrange to find d: d = lambda/sin(theta) but they seem to convert it into d = (1.22 x lambda)/ sin(Theta) for diameter of an nucleus and then d = (0.61 x lambda)/ sin(Theta) for radius.
correct me if i'm wrong..

https://www.youtube.com/watch?v=L0q8u0N5K_Y
this guy explains it very well :smile:

Reply 257

ella97

Do we need to be able to fully derive the equation for the pressure of an ideal gas? I kind of get it but not sure how it'll come up in the exam.

Reply 258

ChillGod

1

Original post by treeporn

For those doing the Turning Points module, could someone tell me whether the the proper value of time dilation t0 is in the moving or rest frame? From my research (which is contradicting the mark schemes) I've been going by the fact that 't' is the proper time in the rest frame and 't0' is the time in the moving frame because the time dilated in the moving frame is greater?

So I've paired up L0 (length is always greatest in the rest frame) with t in the rest frame and L with t0 in the moving frame but the mark schemes indicate that L0 is paired up with t0 meaning time dilated is greatest in the rest frame so I'm dead confused.

I kind of get the concepts but I look at these questions more from ratio point of view so if anyone could clear up my confusion i'd be grateful.

Bro, it just all confuses me. I just think of the example of the twins. The travelling twin is t0 and L0 because to the outside observer, his spaceship contracts. He is t0 because when he comes back to earth, his twin is way older than him. I just keep that in mind when sense checking my answers.