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    (Original post by milliezhao)
    Hey I got the same but instead of simplifying it I just left it as x=-3/4√3ag/5 the minors because it is going left, but I think we need to add the horizontal distance from O when the string was slack?? Same for the y??


    Posted from TSR Mobile
    No you don't have to add the distance from initial position or anything. It is all relative to origin.
    I am saying this 3rd time but using vectors just scraps off all these :P once you take the i as positive x-axis and j as positive y-axis, and then find your initial velocity and position vector nice and clear with correct signs (directions) you have nothing else to worry about.
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    And SHM I got w is √50, a is 0.2, time in the end was 0.296?


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    (Original post by milliezhao)
    And SHM I got w is √50, a is 0.2, time in the end was 0.296?


    Posted from TSR Mobile

    Yeah I got that

    Also 2 posts above, what do you mean by COM question?
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    (Original post by milliezhao)
    For Com question part a I got 5.1 and b I think it was 1.72 or something, anyone got the same?


    Posted from TSR Mobile
    They don't sound familiar to me, do you remember the fractions. They were really big but I still preferred to leave them exact. Btw I spent at least 20 mins checking this question :P
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    (Original post by Alexn159)
    Yeah I got that

    Also 2 posts above, what do you mean by COM question?
    He means centre of mass.
    I got the same for SHM!
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    (Original post by study beats)
    guys i failed this exam really badly, i am crying, how can i get over this...my life is ruined
    I'm sure you did better than you think you did.
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    (Original post by milliezhao)
    For Com question part a I got 5.1 and b I think it was 1.72 or something, anyone got the same?


    Posted from TSR Mobile
    Wasn't part a between 0 and 2?
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    (Original post by Xiroz)
    For those x and y equations, did you remember that they do not start at the origin? initial x position is -4a/5 and initial y is 3a/5
    How many marks do you think I will lose for not putting the initial position?
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    I got 1.31 on the graph.
    Then 1.77 from the base on solid
    Sound familiar to anyone?



    and how many marks do you think I will lose on the last question for putting -gt^2 rather than -1/2gt^2 because I took away an extra -at^2 by using a wrong equation right at the end
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    (Original post by Serpentine111)
    Wasn't part a between 0 and 2?
    Exactly!
    I think very very roughly I got something close to 1.5.
    For second part don't forget to subtract your answer from 2a, i got something like 1.3 maybe...
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    I just remembered the whole centre of mass question and I am quiet sure about it. I will appreciate if you can double check it for me.

    http://i40.tinypic.com/2z6eezt.jpg

    (I was about to do the proving part aswell but I passed that to just get the answer using the formula)
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    (Original post by miketree)
    Should have studied instead of listening to music on your beats.
    i did study, and what beats?
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    (Original post by Joshmeid)
    I'm sure you did better than you think you did.
    i really didnt
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    The paper was simple, i made a stupid mistake as i always do... im expecting to lose maybe 8 - 6 marks all due to subbing 0 into (x+1)^5/5 and getting 0 -.- pretty annoyed but par that it was ok. As for the rest of the answers:
    mu:0.179
    Force question: 2t^2+t=v v=6 x=27/8m
    string question:0.805 (velocity) not sure though, 0.383m travelled
    SHM: show that, root50 and time was 0.296
    COM... 1.51, 0.721 (i got 1.5 and 0.729 close or what)
    Circle... x=vt-a3/5 y=vt-gt^2/2+ a4/5 (may have got the 4/5 and 3/5 mixed up though) i think the velocity was root3ag/5

    please correct me if i am wrong and possibly maybe if anyone can figure how many marks would i lose for that stupid COM i used all the right methods for both parts, i integrated right but my only fault was the mistake with subbing my values, it annoyingly affected my mass as well got 243/5 instead of 242/5 do you think i can get 4 marks on the first part and 3 on the next part?
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    (Original post by VSEPR)
    Also someone had scribbled all over the C3 formulae in the booklet when I tried to check the equation for volume of revolution; it wasn't there and I wonder if some poor soul will get into trouble when they do C3 on Thursday...
    Revolution is in C4
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    (Original post by idknow)
    The paper was simple, i made a stupid mistake as i always do... im expecting to lose maybe 8 - 6 marks all due to subbing 0 into (x+1)^5/5 and getting 0 -.- pretty annoyed but par that it was ok. As for the rest of the answers:
    mu:0.179
    Force question: 2t^2+t=v v=6 x=27/8m
    string question:0.805 (velocity) not sure though, 0.383m travelled
    SHM: show that, root50 and time was 0.296
    COM... 1.51, 0.721 (i got 1.5 and 0.729 close or what)
    Circle... x=vt-a3/5 y=vt-gt^2/2+ a4/5 (may have got the 4/5 and 3/5 mixed up though) i think the velocity was root3ag/5

    please correct me if i am wrong and possibly maybe if anyone can figure how many marks would i lose for that stupid COM i used all the right methods for both parts, i integrated right but my only fault was the mistake with subbing my values, it annoyingly affected my mass as well got 243/5 instead of 242/5 do you think i can get 4 marks on the first part and 3 on the next part?
    I got exactly the same except question except question 7 where I forgot the add the initial position how many marks do you think I will lose? I think for the com question you won't lose more than 3 marks


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    (Original post by milliezhao)
    For Com question part a I got 5.1 and b I think it was 1.72 or something, anyone got the same?


    Posted from TSR Mobile
    That cant be right because the length of it was only 2, I got approximately 1.5 if that's what you mean.
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    study beats,

    Dw I'm sure it wasn't terrible . Ya never know about the boundaries. Just ignore him, doesn't seem to be the nicest of people :P.

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    (Original post by bbcs2k9)
    That cant be right because the length of it was only 2, I got approximately 1.5 if that's what you mean.
    Sorry, I meant 0.51 and 0.7, I was tired :s


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    (Original post by milliezhao)
    F

    I got exactly the same except question except question 7 where I forgot the add the initial position how many marks do you think I will lose? I think for the com question you won't lose more than 3 marks


    Posted from TSR Mobile
    3marks???? i would be really happy but im very sceptical, as for how many you would lose probably 2 accuracy for each answer maybe and if they really aren't lenient a mark for the method so max u should only lose out on 3 but probably 2
 
 
 
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