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AQA A2 MM2B Mechanics 2 – 27th June 2016 [Exam Discussion Thread] Watch

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    (Original post by forestspirit)
    This paper seemed to combine the 'hard' questions from a few other papers from different years with a new twist on them (question 8 similar to june 2014 paper q8 but with two elastic strings, question 5 somewhat similar to june 2011 q8 but more difficult etc.). I think grade boundaries will be around 62/63 for 90 UMS on this paper.
    I'd love it if it was that low but I reckon it's more likely to be around 65-67 for an A*.
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    (Original post by Yo12345)
    Not really. Conservation of energy (1), correct equation (2), putting v>0 (3) Re-arranging to get u = 2root(gl) (4)


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    Can we please stop trying to convince everyone that the incorrect answer 2\sqrt{gl} is correct...
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    I think the point where people may have slipped up on the last question is resolving the reaction force to find the frictional force using the component of weight
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    (Original post by Jm098)
    I think the point where people may have slipped up on the last question is resolving the reaction force to find the frictional force using the component of weight
    Yeah, that's possible, I can see a lot of people slipping up there. Although I swear I did everything right and got 7.05m. Might've made a couple of mistakes here and there then...
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    If i did the correct method on the elastic strings question but forgot to swuare the extensions, how many marks out of 8 would I get?
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    nah that was just 5gcostheta. I think is was writing the extension for the two elastic strings in terms of the distance travelled!
    (Original post by Jm098;m6137639)
    I think the point where people may have slipped up on the last question is resolving the reaction force to find the frictional force using the component of weight
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    (Original post by TheLifelessRobot)
    I'd love it if it was that low but I reckon it's more likely to be around 65-67 for an A*.
    I reckon 66 A*, 61 A, 54 B, 46 C ... for this paper
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    (Original post by TheLifelessRobot)
    I'd love it if it was that low but I reckon it's more likely to be around 65-67 for an A*.
    I'm not sure, last year's paper was 65 for an A* and that paper was more straight forward with numerical answers, as opposed to q5, q6 and q7 of this year's paper which all had variables in the answers. It has been as low as 63 before, so I think it will be at most 64 for A*.
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    (Original post by IrrationalRoot)
    Yeah, that's possible, I can see a lot of people slipping up there. Although I swear I did everything right and got 7.05m. Might've made a couple of mistakes here and there then...
    Hm I'm not sure then! There was EPE in both strings as well. Also I got 1/4mu + 1/2mu not -, do you think they'd only deduct one or two marks providing the working is ok?
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    (Original post by forestspirit)
    I'm not sure, last year's paper was 65 for an A* and that paper was more straight forward with numerical answers, as opposed to q5, q6 and q7 of this year's paper which all had variables in the answers. It has been as low as 63 before, so I think it will be at most 64 for A*.
    Well I wholeheartedly hope you are right. I honestly think 2015 was more difficult overall but I can hope.
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    (Original post by IrrationalRoot)
    Can we please stop trying to convince everyone that the incorrect answer 2\sqrt{gl} is correct...
    Yes it's 2root gl definitely
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    (Original post by Jm098)
    Hm I'm not sure then! There was EPE in both strings as well. Also I got 1/4mu + 1/2mu not -, do you think they'd only deduct one or two marks providing the working is ok?
    Did you remember the second frictional force when taking moments on the ladder? I did that anf got a plus but realised and corrected it
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    Anyone get Ue^-lambda t for the diffirential equation?
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    (Original post by jtebbbs)
    Did you remember the second frictional force when taking moments on the ladder? I did that but realised and corrected it
    Yeahh done that
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    I swear it was root5lg, there was a similar question to that in one of past papers, I think it was after finding expression for T and we had to make T=0
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    for the expression of r in the earlier question, was c= 5i-5j?
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    I got a strange answer for the differential equation but I checked over it quite a few times
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    (Original post by Jm098)
    I think the point where people may have slipped up on the last question is resolving the reaction force to find the frictional force using the component of weight

    100% agree with you mate, I know I did
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    (Original post by Jm098)
    Hm I'm not sure then! There was EPE in both strings as well. Also I got 1/4mu + 1/2mu not -, do you think they'd only deduct one or two marks providing the working is ok?
    No idea, how the marks would work, but I would love to know what the correct answer was, I got 7.05 which is probably wrong due to some silly mistake somewhere.

    If it makes you feel better I probably lost all 7 marks on the ladder question because I can't read and so I took both coefficients of friction to be \mu despite an otherwise perfect method.
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    Oh **** I think they'd ecf it though

    (Original post by IrrationalRoot)
    No idea, how the marks would work, but I would love to know what the correct answer was, I got 7.05 which is probably wrong due to some silly mistake somewhere.

    If it makes you feel better I probably lost all 7 marks on the ladder question because I can't read and so I took both coefficients of friction to be \mu despite an otherwise perfect method.
 
 
 
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