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AQA AS Further Maths (New Spec) - Paper 2 - 17 May 2018 [Exam Discussion]

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Anyone find the question 4 mechanics momentum question a bit annoying?? I think I got it in end but it took me ages because I was getting a negative of what they asked to show then realised it asked for speed not velocity.
Original post by scarlhannan
the LHS of the equation was kinetic energy right?
so I did ML2T-2 = [LT-1]2
I thought of angular velocity just as velocity, not thinking about the fact that it was angle, not length
I reckon quite a few people could have made the same mistake I did, easy to not spot


I definitely agree with you there, they probably hand picked that sort of equation just to trick people.
Original post by 12edwardr
Anyone find the question 4 mechanics momentum question a bit annoying?? I think I got it in end but it took me ages because I was getting a negative of what they asked to show then realised it asked for speed not velocity.



Yeah, question four was annoying, I'm guessing you took the A direction as positive? I wasn't sure whether I had to justify whether the velocity was positive or negative anyway?
Speaking of tricks, did anyone get the first question on the stats paper? I reckon it was zero because integrating between 1 and 1 is zero (and P(X=1) would be so ridiculously small that it is effectively zero, because its continuous) but some people are pretty confident it was a 1/2 or 3/4
Original post by Rooiegent
the best question on stats was by far the chi squared test providing you knew what to do. It was a very good question - did anyone right down the X^2 contribution table just in case? And what where your fave questions?


I included the contribution table but I'm worried I should have quoted the formula.
Original post by DarthYoda
Yeah, question four was annoying, I'm guessing you took the A direction as positive? I wasn't sure whether I had to justify whether the velocity was positive or negative anyway?


Yeah I took A as positive then had to write a note to say that it is the magnitude of this at the end to get the positive version. But it took ages and I tried it loads of times and had to go to the extra pages at the back ahahahah
Reply 26
I know you're meant to combine if the expected is less than 5, but I don't remember the expected being less than 5
Original post by psycholeo
I know you're meant to combine if the expected is less than 5, but I don't remember the expected being less than 5


IMO I think they tried to hide it. Only the top right cell was less than 5, had 4.something in it. They also had given you that value so you would be less likely to notice.
What did everyone get for whether he'd go into water? I just set up CoE equation then let v=0 so solve a quadratic. I got he wouldn't
Original post by Joel_Bridgwater
What did everyone get for whether he'd go into water? I just set up CoE equation then let v=0 so solve a quadratic. I got he wouldn't


Yes, I got that he wouldn't with the same method. Someone else instead substituted extension as 25 and proved that there were no real roots.

For part b did you say his height might make him enter the water? (He is likely over 1.5m)
I had the same problem with Q4 with getting opposite sign to what they wanted. But if you assume they both go in the same direction after they collide it seemed to fix it, although both ways will work i presume
Original post by Joel_Bridgwater
I had the same problem with Q4 with getting opposite sign to what they wanted. But if you assume they both go in the same direction after they collide it seemed to fix it, although both ways will work i presume


After they collide they are both going in the B direction I think?
Original post by DarthYoda
Yes, I got that he wouldn't with the same method. Someone else instead substituted extension as 25 and proved that there were no real roots.

For part b did you say his height might make him enter the water? (He is likely over 1.5m)


yeah i got something like 48.5 below where he started. That's a good point about him being over 1.5, but i thought since his centre of mass will most likely be around his stomach, then from his centre to head isn't 1.5m but its a valid point. I just said about resistance forces but i think your suggestion is right
Original post by DarthYoda
After they collide they are both going in the B direction I think?


Yeah i think so
Original post by Joel_Bridgwater
yeah i got something like 48.5 below where he started. That's a good point about him being over 1.5, but i thought since his centre of mass will most likely be around his stomach, then from his centre to head isn't 1.5m but its a valid point. I just said about resistance forces but i think your suggestion is right


I think resistive forces is a valid answer as well, because it would mean energy is not conserved within the system.
Original post by Joel_Bridgwater
yeah i got something like 48.5 below where he started. That's a good point about him being over 1.5, but i thought since his centre of mass will most likely be around his stomach, then from his centre to head isn't 1.5m but its a valid point. I just said about resistance forces but i think your suggestion is right

Didn’t it say his feet were attached to the end of the rope, so surely it would b if he was 1.5m tall not if his center I’d mass was 1.5m away ??? I can’t remeber tbh ahah
Original post by 12edwardr
Didn’t it say his feet were attached to the end of the rope, so surely it would b if he was 1.5m tall not if his center I’d mass was 1.5m away ??? I can’t remeber tbh ahah


Yeah thats true, i hope they allow different answers
Original post by Joel_Bridgwater
Yeah thats true, i hope they allow different answers


I think they will, they often have a selection for assumptions.
Hi I want to practice for my future As mock exams , could anyone please make a list of the questions in this exams and key tricks in them ? It would help alot.Our teacher said she would copy tricks from these exams in our exams though she will change them significantly ,Thanks.Also if someone has access to paper could you message me please ? ThanksThe mechanics and stats paper please
I know this is very weird to ask something after soo long time but we have got a test on 2018 Stats+Mech paper next week. So do any of you remember any questions for mechnics part that came up? Thanks in advance!!

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