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The Edexcel M3 (14/06/12 - AM) Revision Thread

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    Hey, how many people here are sitting this exam, and how is preparation going?
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    I started revising for it yesterday as the M2 exam gave me a great buzz I'm going through all the review exercises first and then I'm going to go through all the exam papers (my revision plan for all my maths modules now ha). I'm approximately halfway though the review exercise (question 48/105), just started the SHM questions
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    (Original post by browb003)
    I started revising for it yesterday as the M2 exam gave me a great buzz I'm going through all the review exercises first and then I'm going to go through all the exam papers (my revision plan for all my maths modules now ha). I'm approximately halfway though the review exercise (question 48/105), just started the SHM questions
    I heard the M2 exam was very hard, how did you find it? What mark do you think you got?
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    It was harder than the previous M2 exams, but I think I've gotten everything correct for it But it certainly was more challenging than many of the previous M2 papers. (one of the questions that came up was very similar to one of the questions in the M2 book's review exercise (the one on impulse), and I would have struggled with the question if I hadn't seen it before; made me smile in the exam)
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    (Original post by browb003)
    It was harder than the previous M2 exams, but I think I've gotten everything correct for it But it certainly was more challenging than many of the previous M2 papers. (one of the questions that came up was very similar to one of the questions in the M2 book's review exercise (the one on impulse), and I would have struggled with the question if I hadn't seen it before; made me smile in the exam)
    Nice one
    How long did it take you to learn M3?
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    About 3 weeks, and I taught it to myself (same as M2). I think that I'll actually get the best grades with the modules that I am teaching myself as then I go through every single question (more or less) in the books, although I'm doing that for C4 now too
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    (Original post by browb003)
    About 3 weeks, and I taught it to myself (same as M2). I think that I'll actually get the best grades with the modules that I am teaching myself as then I go through every single question (more or less) in the books, although I'm doing that for C4 now too
    Cool, which chapter would you say is the hardest?
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    (Original post by jukebox123)
    Cool, which chapter would you say is the hardest?
    I'm not sure to be honest, at the moment it's probably the statics of rigid bodies chapter mainly because that's the chapter that I haven't gone over lately, and I'm probably quite rusty with the questions. But when I've gone over them all, I think that they're all about the same difficulty
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    (Original post by browb003)
    I'm not sure to be honest, at the moment it's probably the statics of rigid bodies chapter mainly because that's the chapter that I haven't gone over lately, and I'm probably quite rusty with the questions. But when I've gone over them all, I think that they're all about the same difficulty
    Ok, what other modules did you sit over the past few weeks, if any?
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    Only M2 for maths, but I've sat both AS Physics papers for OCR in May. Which chapter do you find the most difficult for M3, and what exams have you sat so far?
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    (Original post by browb003)
    Only M2 for maths, but I've sat both AS Physics papers for OCR in May. Which chapter do you find the most difficult for M3, and what exams have you sat so far?
    Im only on chapter 3 at the moment- hoping to finish it within a week...
    I have sat S2 so far.
    How long did it take you to learn SHM?
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    A few days I think, it seemed to drag on for a while if I recall correctly, but the questions are very satisfying to answer if you get them correct ha
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    (Original post by browb003)
    A few days I think, it seemed to drag on for a while if I recall correctly, but the questions are very satisfying to answer if you get them correct ha
    On the secong page of SHM, have they confused the 'a's, because the 'a's on the graph are not the same as the a for amplitude? Are they meant to be the same, because amplitude is maximum displacement, and the peaks and troughs on the graphs have different 'a's? Do you know what I mean? Sorry, it's really frustrating
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    Yeah I see what you mean, replace what they've written with  x = asin(\omega t + \phi) as it makes more sense.

    The  \phi symbol respresents how far the SHM is through an oscillation when t= 0 say, (known as phase http://en.wikipedia.org/wiki/Phase_%28waves%29 ). The book's used the letter a (well actually it's alpha, but the font looks extremely similar to an a) to represent it however which makes it unnecessarily confusing.

    However the questions in M3 never use this 'phase through the oscillation' stuff, as the SHM in the questions always start either at 0 displacement or at maximum displacement (ie x = amplitude), and never at some way through an oscillation. So on the 1st and 2nd pages of SHM, you'll only deal with Cases (i) and (ii), and never (iii) in M3
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    (Original post by browb003)
    Yeah I see what you mean, replace what they've written with  x = asin(\omega t + \phi) as it makes more sense.

    The  \phi symbol respresents how far the SHM is through an oscillation when t= 0 say, (known as phase http://en.wikipedia.org/wiki/Phase_%28waves%29 ). The book's used the letter a (well actually it's alpha, but the font looks extremely similar to an a) to represent it however which makes it unnecessarily confusing.

    However the questions in M3 never use this 'phase through the oscillation' stuff, as the SHM in the questions always start either at 0 displacement or at maximum displacement (ie x = amplitude), and never at some way through an oscillation. So on the 1st and 2nd pages of SHM, you'll only deal with Cases (i) and (ii), and never (iii) in M3
    So  \phi shows where the particle starts relative to O?
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    (Original post by jukebox123)
    So  \phi shows where the particle starts relative to O?
    It sort of more moves the wave along the x axis/time axis, which in turn does change the displacement of the particle from O (when t= 0), as  \phi shifts the graph left or right.

    Fortunately it's not in the spec

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    (Original post by browb003)
    It sort of more moves the wave along the x axis/time axis, which in turn does change the displacement of the particle from O (when t= 0), as  \phi shifts the graph left or right.

    Fortunately it's not in the spec

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    Oh ok, so basically when t=0, the particle starts its motion from the origin?
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    (Original post by jukebox123)
    Oh ok, so basically when t=0, the particle starts its motion from the origin?
    In one of the cases yes;

    Case (i)

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    When t = 0, x = 0
    ie the oscillation starts from the origin
    For this, you would use  x = asin(\omega t) as the displacement - time graph follows that of a sine graph.



    Case (ii)

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    When t = 0s, x = AMPLITUDE
    ie then oscillation starts from the displacement furthest away from the origin
    In this case, you'd use  x = acos(\omega t) as the displacement - time graph follows that of a cosine graph

    Hopefully this distinguishes between the two 'types' of oscillations that M3 deals with
Updated: June 14, 2012
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