The Physics PHYA2 thread! 5th June 2013

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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can anyone help with June 2010 Q1C?

Where abouts is this in the book? And thank you!!

Posted from TSR Mobile

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
Posted from TSR Mobile

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.

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.

Again thanks. Do you know what page this is in the textbook?


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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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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

Someone posted it a page or two back


Posted from TSR Mobile

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

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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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.