The Physics PHYA2 thread! 5th June 2013

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Reply 1940

Forgive moi if I'm wrong but for the Phase difference question wouldn't In Phase & Anti phase be enough ???

I don't think so - that is stating the phase relationship, not the phase difference? Also, I don't think you can be sure of either of those, as it wasn't a standing wave. :rolleyes:

Reply 1941

Big-Daddy

Original post by navyspaces

I don't think so - that is stating the phase relationship, not the phase difference? Also, I don't think you can be sure of either of those, as it wasn't a standing wave. :rolleyes:

Is there an unofficial mark scheme? I got 1/2*pi and 3/2*pi respectively for that question.

Reply 1942

navyspaces

Original post by HenryD

Have to start work on the PAT soon, and start my extended project on something in physics. So much work.

Starting on the PAT now is interesting... I didn't start my TSA until September time! Won't you have forgotten most of it by then?

Reply 1943

TheSnail

Original post by navyspaces

Me too; my university place is effectively resting on this retake, as if I don't ace it I have to make up for it in Units Four and Five, which would be a lot more effort... Very pleased to have just realised that I didn't get all the TIR stuff wrong. In a burst of post exam madness, my friend convinced me that TIR worked the opposite way round... :smile:

I'm debating whether to choose to carry on bio,chem and maths or bio,chem and physics next year. Can you possibly give me your opinion on A2 physics?

Reply 1944

Anythingoo1

What value did people get as the spring constant?

Reply 1945

navyspaces

Original post by Big-Daddy

Is there an unofficial mark scheme? I got 1/2*pi and 3/2*pi respectively for that question.

Yes, I got that, and that's what it is I believe!

The UnMS is on the first page of this thread?

Reply 1946

Zozzy

Is there an unofficial mark scheme yet?

Reply 1947

navyspaces

Original post by Anythingoo1

What value did people get as the spring constant?

By calculating the gradient of the graph, I got either 1100 or 1200 (I've forgotten) and I verified this by trying out a few single values in F=k x (extension) :smile:

Reply 1948

HenryD

Original post by Davelittle

Regarding acceleration in oil it has been on another past paper, basically the same 6 marker so the graph would curve :smile:

Original post by gandanmo

bro you know question 4G i just wrote it would be less, as it was 1 mark, do you think i lost it ? AND HOW IS THE DRaWING OF THE RED LASER LOOK LIKE IN QUESTION 7? SORRY I KEEP THINKING OF QUESTIONS!

Can you remember the wording of the question on 4G? I can't haha.
And I drew it as wider and with lower intensity. I'm sure it was wider and fairly sure about the intensity part but not 100%.

(edited 10 years ago)

Reply 1949

navyspaces

Original post by g.k.galloway

I'm debating whether to choose to carry on bio,chem and maths or bio,chem and physics next year. Can you possibly give me your opinion on A2 physics?

That'd depend on what you want to do at university. Send me a message about it :smile:

Reply 1950

Anythingoo1

Original post by navyspaces

By calculating the gradient of the graph, I got either 1100 or 1200 (I've forgotten) and I verified this by trying out a few single values in F=k x (extension) :smile:

Nice I had 1250 I think but that should be fine seeing as they're always quite lenient with the values it can take

Reply 1951

navyspaces

Original post by HenryD

I made the mistake of forgetting the curve down, but I do agree. When the ball hits the oil, it's decelerated, as it's more dense than air. Isn't that all we need to know? :smile:

Reply 1952

gandanmo

Original post by HenryD

Disagree about the acceleration, it's not necessary if you think the ball is already travelling faster than it would in the oil. If you look at the height it was dropped from then it would've been, so it would've decelerated into a curve. But they may allow both as technically there isn't a way to really know this.

Yeah this is what I'm expecting it to be too.

I think probably two :smile:

Possibly three but more likely 2.

That is a single slit diffraction graph. But it would be blue on the inside, red on the outside.

bro you know question 4G i just wrote it would be less, as it was 1 mark, do you think i lost it ? AND HOW IS THE DRaWING OF THE RED LASER LOOK LIKE IN QUESTION 7? SORRY I KEEP THINKING OF QUESTIONS!

Reply 1953

HenryD

Original post by navyspaces

Starting on the PAT now is interesting... I didn't start my TSA until September time! Won't you have forgotten most of it by then?

It's more just a general covering of things they can test you on which my syllabus hasn't covered (and I self taught half anyway) because they can test on all kinds of things. And I'm away a lot over summer, have the extended project to do and football starts again a couple of months before so I'll be pretty busy haha. How much revision did you do for it?

Original post by gandanmo

bro you know question 4G i just wrote it would be less, as it was 1 mark, do you think i lost it ? AND HOW IS THE DRaWING OF THE RED LASER LOOK LIKE IN QUESTION 7? SORRY I KEEP THINKING OF QUESTIONS!

Can you remember the wording of 4G?
And I put it as wider and less intense. I'm sure it was wider and reasonably confident it was less intense but not 100%.

(edited 10 years ago)

Reply 1954

navyspaces

Original post by HenryD

I know how it is, I thought about applying for Physics and Philosophy for a little while. :smile:

I don't really remember - two or three weeks perhaps, sparsely. I just did all the past papers and hoped for the best. :smile:

I suppose the TSA relies more on how you respond to what's presented to you though, rather than having the scientific knowledge already in your head. Though, my TSA essay ended up being about the science of artificial intelligence, which is perhaps the same thing! :rolleyes:

Reply 1955

gandanmo

Original post by HenryD

Can you remember which one?
And I'd expect marks to be given for both, there was no way for one to calculate the terminal velocity in the oil but we shall see. Both are correct but depend upon whether you think it impacts above or below the terminal speed.

Can you remember the wording of the question on 4G? I can't haha.
And I drew it as wider and with lower intensity. I'm sure it was wider and fairly sure about the intensity part but not 100%.

yeah for 4G it was something like without any further calc would the work done by loading be less or more than un loading, i wrote less workdone when unloading, as less distance is done, and workdone is force x distance. is that wrong? aah i drew a wider peak but same intensity also mine were more spread out, did it have to be inline with blue laser? would i get 1 out of 2 marks for that?

Reply 1956

HenryD

Original post by navyspaces

I made the mistake of forgetting the curve down, but I do agree. When the ball hits the oil, it's decelerated, as it's more dense than air. Isn't that all we need to know? :smile:

The curve will only be 1 mark :smile:

And I was just saying how you could have two perfectly valid different curves depending on what you think the terminal speed in the oil and the speed it reaches in the air are.

Original post by Davelittle

sorry I misread your post!

Don't worry about it :smile:

Reply 1957

Aarongreatbanks

Original post by HenryD

I'm not sure on that one. I'm thinking the three marks will be for, 1 a straight line up to the first dotted line, 2 a sharp curve downwards after that line, 3 a straight line at the end of that curve. So I think you'll probably be ok but I can't be 100%.
And you're welcome :smile:

The six marker looks pretty good to me, hard to tell with them cause you can lose marks for your writing and communication etc but I wouldn't be surprised if you got 5 or 6.
That oil graph question was nasty. It depends on whether you think it'll carry on accelerating in the oil or not. But you'll definitely get a mark for the straight line at the start and the flat line at the end. So at least 2/3 and possibly 3/3, difficult to tell.

For 1a I rushed it near the end! I scribbled out my inital answer of 7200-1200=6000 to do the square root of 6000 squared plus the 1000 squared and this got something like 6082....I said this is about 6100 but the 2 above the 1000 was a bit messy and I didn't make the square root long enough originally so I had to add to the line to make it cover all of the numbers. Therefore my workings were okay but not the clearest. Will I get both marks here as they will be able to see/guess what I did for the method as I would have got the correct figures for the answer

Reply 1958

HenryD

Original post by navyspaces

I know how it is, I thought about applying for Physics and Philosophy for a little while. :smile:

I don't really remember - two or three weeks perhaps, sparsely. I just did all the past papers and hoped for the best. :smile:

I'm still considering whether to go pure physics or physics and philosophy. I want to go into physics but I do love philosophy so I'm really not sure.
And yeah that's true, with physics you need more of a background in the general concepts so that you can at least understand the question. Plus half of it will be maths and I stupidly didn't pick FM so I'll need to do some of that too.

Original post by gandanmo

No that's right, less work is done because there's less force per amount of extension :smile:

Or as you put it there so you'll get the mark.
Definitely 1, possibly 2 I'm still not sure whether I'm right about the intensity :smile:

Original post by Aarongreatbanks

There's no way you could realistically guess 6082 (which was the answer). If they can see that and can see something to do with pythagoras you'll get the marks so I think you'll be fine.

(edited 10 years ago)

Reply 1959

yorkshire.lad

Original post by lebron_23

Just quickly, can anyone actually confirm what they got for the efficiency question? I seem to recall hearing various answers from people after the exam but not once did I hear what I was hoping for.

Also, if anyone is curious as to what the grade boundaries have been for the papers since June 2009, I'll be attaching a document that was rather nicely posted a bit eariler on this thread. Sorry creator of the Excel document, I hope I haven't violated any copyright laws!

Having them in a table just seems so much easier than using AQA's website to look for each year individually.. Ugh!