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The Physics PHYA2 thread! 5th June 2013 Watch

  • View Poll Results: What mark do you think you got out of 70?
    0-20
    6
    3.00%
    21-40
    12
    6.00%
    41-50
    29
    14.50%
    51-60
    79
    39.50%
    61-70
    74
    37.00%

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    (Original post by StalkeR47)
    Wait..... How can it be a straight line? If the ball is dropped from the rest, it should accelerate until it hits the oil surface. So, the graph is curve showing that velocity is increasing more with less time.
    This is incorrect, it accelerates at the rate of gravity so yes the linear line is correct then it hits the oil therefore a drag force is IMMEDIATELY acting upon it, this means that the acceleration will slow down lol...
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    (Original post by kingmango)
    Anybody know? for the energy stored in the spring, i counted 43 squares, so i did 43 x 0.025 = 1.075J. Would this be right???
    yep that's right the right answer seems to round to 1J
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    Did you have to count the squares or could you have used 3 triangles?
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    (Original post by FLLF)
    The diameter was 2.2x10-2

    So W = (4/3) * pi * (2.2x10-2/2)^3 * 8100 * 9.81
    Ahh I must of done a calculator error then might get 2/3 marks hopefully because I did that method
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    (Original post by ClarkyC...)
    Right the diameter was 2.2x10-3 of the sphere and the density was 8100kgm-3. I can't get to 0.44N what am I doing wrong
    Spoiler:
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     V = \frac{4}{3}\pi(\frac{D}{2})^3

    sub in your D value and type into the calculator, you will get  5.58\times10^-6 . then using  p = \frac{m}{V} rearrgange to get  pV = m and sub in the density given 8100 and the V you just found out, giving you 0.0452kg, you would then times that by 9.81 since they want weight giving you 0.44N
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    (Original post by ClarkyC...)
    Ahh I must of done a calculator error then might get 2/3 marks hopefully because I did that method
    What was your final answer? Lots of people did the radius squared rather than cubed, so they got an answer of 44 or something?
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    Grade boundary predictions anyone? I think an A will be the highest it's ever been in this paper
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    (Original post by FLLF)
    What was your final answer? Lots of people did the radius squared rather than cubed, so they got an answer of 44 or something?
    No no I got a really big answer, not sure why. As I said probably a calculator error although I don't know how I could do that
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    (Original post by PickwickianGeek)
    Grade boundary predictions anyone? I think an A will be the highest it's ever been in this paper
    I doubt it, it's more likely to be average.
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    The area under the graph didn't have to be to 1 s.f....
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    (Original post by PickwickianGeek)
    Grade boundary predictions anyone? I think an A will be the highest it's ever been in this paper
    I doubt it, have you seen how many people have dropped marks just on this forums and a lot of those people are aiming for top unis!
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    (Original post by kingmango)
    Anybody know? for the energy stored in the spring, i counted 43 squares, so i did 43 x 0.025 = 1.075J. Would this be right???
    i got about 51 was quite precise
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    (Original post by Davelittle)
    Isn't decelerating when its velocity decreases?
    Although what I don't understand is that there was a very similar question in June 09 and it allowed deceleration
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    (Original post by kingmango)
    Anybody know? for the energy stored in the spring, i counted 43 squares, so i did 43 x 0.025 = 1.075J. Would this be right???
    did you do it up to the end of the graph?
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    (Original post by StalkeR47)
    Yep! around 44-46/70 for an A.
    SERIOUSLY ??? That much for an A? Is that how it is normally?
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    (Original post by ClarkyC...)
    Although what I don't understand is that there was a very similar question in June 09 and it allowed deceleration
    Hmmmmm strange!

    You could always request your script back to see
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    (Original post by Mr__H)
    SERIOUSLY ??? That much for an A? Is that how it is normally?
    seems too low for an A
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    (Original post by Mr__H)
    SERIOUSLY ??? That much for an A? Is that how it is normally?
    http://www.aqa.org.uk/exams-administ...t-marks-to-ums

    Go there and put the unit as PHYA2 and look for yourself.....
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    (Original post by Davelittle)
    I doubt it, have you seen how many people have dropped marks just on this forums and a lot of those people are aiming for top unis!
    I haven't gone through this thread! I was only going off how my classmates found it. Most found it easy but I only found it average. I'm hoping it's 49/50/51 for an A. Hopefully I can scrape an A
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    (Original post by kingmango)
    Anybody know? for the energy stored in the spring, i counted 43 squares, so i did 43 x 0.025 = 1.075J. Would this be right???
    yep that is correct, i done it the AQA way, where by they count the whole number of sqaures seperately, and then all other partial squares as ONE varying from 3/4 of a square to 1/16 of a square as long as it shows a part of a square you add it as one, then you add up all the partial squares and divide by 2 giving you an approx value for whole squares, add that to your original no. of squares and times that by area of one square.

    just like in question 4)e)i) january 2012 paper, take a look at the mark scheme and look how they did it http://www.tomred.org/uploads/7/7/8/...s_jan_2012.pdf
 
 
 
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