M3 Pre-Exam thread (edexcel)

i have a few questions that are realy annoying me, can someone help?

1) for the weird triangle question with sectors cut out, do you get any marks if you find the com using medians in a triangle instead of calculus? (i paniced)

2) what do people think the grade boundaires are? (it was the worst paper i've ever done)

3) what do you reckonthe raw mark for 89 ums would be as that is what i need for the A*

Yeh you'll get a few, I flopped whole of q6


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you'd lose the final accuracy mark and probably 2 method marks, possibly one more accuracy mark :/ hope you managed the COM qs ok... I didn't :P

Question 4? I got the first bit, which was the 'show that' question. I never even wrote a final answer for k, I tried finding the new COM using (M+kM)y=... and I used tan 45=1 and equated them but I must have done something wrong along the way because I ended up with equal number of k's on both sides so I just gave up. I think they usually want you to use moments in that question so I probably lost all 6 marks

I did exactly the same as you for that :/ and it was out of 5 not 6

Did your k's cancel out too? How many marks do you think the examiners might give us if they think our method is valid, with just a few slip ups?

i didnt think this was too bad actually, but then again thats what i thought about jan and i got a D!

so proud of myself for being able to do 6a (y=a - 1/sqrt(3)x right?) but 6b really messed me up. do you reckon i could get any marks for using the CofM of a sector formula with pi/4 ?

and the whole find k, that was literally impossible for me! i just couldn't get my head around using the fact that the angle was 45 as well as that the new CofM must be below the point of suspension. oh well

I actually don't know how the marks will be rewarded myself. I assume some marks would be rewarded for calculating the correct centre of mass and are of the triangle and the sectors so maybe 3-4 marks for an incomplete answer?

On 1b) If you found the constant, then rearranging to get x in terms of t would be a mark and then a final accuracy mark? So maybe 4 out of 6?

I think a lot of people like myself freaked out yesterday because the questions felt so weird, I mean, only FM candidates do M3 and still most people here say it's hard. I'm hoping that my generous self-mark of 57 would at least get me 70UMS.

And here's the solution to 6a? just in case you're interested:

I'll virtually choke one anyone who writes they got 75 right now..... There was a d*ckwad that did that on the m2 thread, about 3 times... I thought m2 was the worst paper, little did I know m3 was worse


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That's not too bad then, to be honest I'll settle for 1 or 2 marks for that, my head was all over the place after seeing the complexity of that question at the time!

That sounds good to me, I think that's fair seen as though I did the bulk of the work, I was just a moron and didn't read the question fully :')

I was the same, the paper seemed routine-like to me initially, but then when it came to question 6, I died a little inside xD I'm sure you'll get that, if not more. The scaling should be very generous for this exam going of most people's reactions..

I read through it thanks, I did revise the proofs, but just didn't clock on in the exam. Wasn't expecting them to ask it really.

Thanks for helping me stay sane! So worried about opening my results now, just because of this M3 exam

Thanks!

I'm expecting:

65-67 full ums (majority dropped 6 marks in one of the bigger questions ==> most lost 12 with 2 of either finding k, proving COM or 1b being the main culprits)
61 A* (hopefully lower =[)
56 A
53 B (smaller jump, as I thought the paper disregarding a few of the harder questions was easier than usual?)
49 C
42 D
38 E