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# The Physics PHYA2 thread! 5th June 2013 Watch

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1. (Original post by SortYourLife)
This is jut rough aha:

You'd have two wires of equal length (measured with a ruler) suspended, measuring the diameter of the one you want to determine youngs modulus for with a micrometer, in several places to get an average

You'd have a set of weights to apply a force to the wire you want to determine the Young's modulus for, the other wire is purely for control, due to temperature changes or whatever.

You'd apply different forces and note down the force applied and the extension of the wire, measured with the one I've forgotten the name of, starts with a v maybe? And take a few readings with an average found

Do this for at least 6 forces.

Plot a graph of force on the y axis and extension on the x, should be a straight line.

Young's modulus is (force*original length) / (extension*cross sectionalarea)

You'd find the area using the diameter before and A=(Pi) r^2 for a circle.

The gradient of the graph sorts out the force over extension, so you'd take the gradient, multiply by the original length of the wire, and divide by the cross sectional area

Something like that anyways, there may be more points you need to get in
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Where abouts is this in the book? And thank you!!

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2. (Original post by pilotluke1)
can anyone help with June 2010 Q1C?
Yes, why not! I just did this question right now just for you. Ok, What I did was I drew a simple force diagram. Assuming that the bike is just a 1.3m ruler. This makes life much easier for me to solve every moment question. I have an attachment for you so that you can understand better. Sorry for the poor quality of the image. Here is my attachment.
Attached Images

3. (Original post by eilish1903)
Where abouts is this in the book? And thank you!!

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Will have a look for you now and no worries, really hoping this is the 6 marker!

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4. (Original post by SortYourLife)
This is jut rough aha:

You'd have two wires of equal length (measured with a ruler) suspended, measuring the diameter of the one you want to determine youngs modulus for with a micrometer, in several places to get an average

You'd have a set of weights to apply a force to the wire you want to determine the Young's modulus for, the other wire is purely for control, due to temperature changes or whatever.

You'd apply different forces and note down the force applied and the extension of the wire, measured with the one I've forgotten the name of, starts with a v maybe? And take a few readings with an average found

Do this for at least 6 forces.

Plot a graph of force on the y axis and extension on the x, should be a straight line.

Young's modulus is (force*original length) / (extension*cross sectionalarea)

You'd find the area using the diameter before and A=(Pi) r^2 for a circle.

The gradient of the graph sorts out the force over extension, so you'd take the gradient, multiply by the original length of the wire, and divide by the cross sectional area

Something like that anyways, there may be more points you need to get in
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is it vernier callipers you're thinking of?
5. (Original post by pilotluke1)
can anyone help with June 2010 Q1C?
Need anymore help? Just ask me.
6. (Original post by StalkeR47)
Yes, why not! I just did this question right now just for you. Ok, What I did was I drew a simple force diagram. Assuming that the bike is just a 1.3m ruler. This makes life much easier for me to solve every moment question. I have an attachment for you so that you can understand better. Sorry for the poor quality of the image. Here is my attachment.
Thanks the ruler analogy is quite helpful! For the first line of working what formula is that? This type of question has come up 3 times since jan 2010

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7. (Original post by pilotluke1)
Thanks the ruler analogy is quite helpful! For the first line of working what formula is that? This type of question has come up 3 times since jan 2010

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No problem. You just have to use Moment= force times perpendicular distance to the direction of the force. So, since the question says "by taking the moments about B", all you have to do is assume that the point 'B' is your moment point so the point A times the distance to the point B(which is out moment point) is equal to all the forces acting on the ruler times the distance up to our moment point (B). This problem is often seen as double support problem.
8. (Original post by StalkeR47)
No problem. You just have to use Moment= force times perpendicular distance to the direction of the force. So, since the question says "by taking the moments about B", all you have to do is assume that the point 'B' is your moment point so the point A times the distance to the point B(which is out moment point) is equal to all the forces acting on the ruler times the distance up to our moment point (B). This problem is often seen as double support problem.
Again thanks. Do you know what page this is in the textbook?

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9. (Original post by pilotluke1)
Again thanks. Do you know what page this is in the textbook?

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No problem! I have a 'Nelson Thornes AQA Physics A' revision book. The page number for this one is 99. And if you need any more help, just ask me.
10. Can anyone tell me the main types of questions and topics that come up that are worth the most marks?
11. (Original post by SortYourLife)
Will have a look for you now and no worries, really hoping this is the 6 marker!

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Assuming you've got the nelson thrones book, there's a little bit at the bottom of page 167 and a diagram showing what I just said on 168, but tbh there isn't a lot on it. I know we did it as an experiment as a whole class of us the first time I was learning it though

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12. Yeah I have the Nelson thornes book. Thank you!! I guess I'm just gonna have to learn the mark scheme for this question!!
U really helped me!! Thanks

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13. (Original post by PickwickianGeek)
Can anyone tell me the main types of questions and topics that come up that are worth the most marks?
They like to ask most of the topics within the book, Youngs modulus, refraction,diffraction being the most common questions for the waves topic. Mechanics is almost always full of moments, resolving and SUVAT questions, best way to revise is going through the past papers!

P.S I've done all but 1 past paper and i really need the January 2013 paper for UNIT (PHYA2) I have got A's throughout all the past papers and I somehow only got a D in the January exam, I would be very happy if someone could please post the Paper
14. (Original post by MattyBirkin)
They like to ask most of the topics within the book, Youngs modulus, refraction,diffraction being the most common questions for the waves topic. Mechanics is almost always full of moments, resolving and SUVAT questions, best way to revise is going through the past papers!

P.S I've done all but 1 past paper and i really need the January 2013 paper for UNIT (PHYA2) I have got A's throughout all the past papers and I somehow only got a D in the January exam, I would be very happy if someone could please post the Paper
Someone posted it a page or two back

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15. (Original post by SortYourLife)
Someone posted it a page or two back

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Yes, page 11, somewhere near the top.

(Original post by MattyBirkin)
They like to ask most of the topics within the book, Youngs modulus, refraction,diffraction being the most common questions for the waves topic. Mechanics is almost always full of moments, resolving and SUVAT questions, best way to revise is going through the past papers!

P.S I've done all but 1 past paper and i really need the January 2013 paper for UNIT (PHYA2) I have got A's throughout all the past papers and I somehow only got a D in the January exam, I would be very happy if someone could please post the Paper
But I'll upload it just incase something goes wrong/can't find it. I also have the mark scheme if anyone needs it, but I believe that the MS is more readily available online than the QP.
Attached Images
16. AQA-PHYA2-QP-Jan13.pdf (670.0 KB, 546 views)
17. AQA-PHYA2-W-MS-JAN13.pdf (182.1 KB, 237 views)
18. (Original post by StalkeR47)
No problem! I have a 'Nelson Thornes AQA Physics A' revision book. The page number for this one is 99. And if you need any more help, just ask me.
Hey StalkeR47,

How you doing, how's revision going for this physics exam?

Wondered if you could help me on 7e and 7bii

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Attached Images

19. (Original post by Jimmy20002012)
Hey StalkeR47,

How you doing, how's revision going for this physics exam?

Wondered if you could help me on 7e and 7bii

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Hey I am fine! I think this is from jan 2013 right? I have got the past paper but not the mark scheme. Just give me few minutes and I will post the answer to those question. Revision is going really well and I am very confident on unit 2 now. But I am just a bit lazy now and I can not be bothered anymore with the revision. HAHA. 2 mins m8, I will help you. What about you, How is your revision going and how many exams have you got now? I have 3 more to go and I will finish all my exams on 6th of june. Also m8, could you please tell me how to move on to another paragraph? I hate writing lods in 1 paragraph. Thanks.
20. (Original post by lebron_23)
Yes, page 11, somewhere near the top.

But I'll upload it just incase something goes wrong/can't find it. I also have the mark scheme if anyone needs it, but I believe that the MS is more readily available online than the QP.
Please post the mark scheme as soon as you can Thanks for the QP.
21. Could anyone please explain why the control wire in the Searle's apparatus negates the effect of temperature? I don't understand this :/
22. (Original post by StalkeR47)
Please post the mark scheme as soon as you can Thanks for the QP.
No problem. I have updated my initial post, it now has the QP and the MS.

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