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AQA Physics PHYA4 - Thursday 11th June 2015 [Exam Discussion Thread] Watch

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    (Original post by QueNNch)
    Hey guys does anyone know how to calculate the time period for this:
    January 2011



    The correct answer is B but my calculations can never get that answer.
    Apparently we are supposed to use ω2r = 9.81

    Thanks
    mg=mw²r
    g=w²r
    T²/4π²=r/g
    T=√(4π²r/g)
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    Anybody know of any good videos for magnetic fields?
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    What are the unit for impulse and change in momentum


    Posted from TSR Mobile
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    (Original post by QueNNch)
    Hey guys does anyone know how to calculate the time period for this:
    January 2011



    The correct answer is B but my calculations can never get that answer.
    Apparently we are supposed to use ω2r = 9.81

    Thanks
    If objects are to appear weightless then their centripetal force is their weight, plug into formula and out pops ur answer
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    (Original post by Fvthoms)
    Anybody know of any good videos for magnetic fields?
    might help https://www.youtube.com/watch?v=MJGR...Xhudf6&index=6
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    (Original post by fvthoms)
    anybody know of any good videos for magnetic fields?
    dr physics a - youtube
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    (Original post by QueNNch)
    Hey guys does anyone know how to calculate the time period for this:
    January 2011



    The correct answer is B but my calculations can never get that answer.
    Apparently we are supposed to use ω2r = 9.81

    Thanks
    just did it calc and got 1.4
    9.81 divided by radius of earth
    square root ans
    ω= 2 pi / T
    2pi / ans = T in seconds
    Convert to hours
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    Cheers 👍

    Edit: Vid was just what I needed. Repped.
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    (Original post by QueNNch)
    Hey guys does anyone know how to calculate the time period for this:
    January 2011



    The correct answer is B but my calculations can never get that answer.
    Apparently we are supposed to use ω2r = 9.81

    Thanks
    Hope this helps! Name:  image.jpg
Views: 57
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    (Original post by C-king)
    Attachment 424989
    Can someone pls help me on this have no clue
    BUMP
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    (Original post by gcsestuff)
    What are the unit for impulse and change in momentum


    Posted from TSR Mobile
    Impulse=∆momentum=kgms-1=Ns
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    (Original post by JaySP)
    mg=mw²r
    g=w²r
    T²/4π²=r/g
    T=√(4π²r/g)
    Cheers.
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    (Original post by QueNNch)
    Hey guys does anyone know how to calculate the time period for this:
    January 2011



    The correct answer is B but my calculations can never get that answer.
    Apparently we are supposed to use ω2r = 9.81

    Thanks
    mw^2r = GMm/r^2

    rearranges to

    w = (GM/r^3)^1/2

    You get the answer in seconds, so divide it by 3600 and it should be 1.4 hours.

    Make sure you cube the radius
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    (Original post by Dante991)
    yeah me too, 19 was just like what
    Tbh I'm like that with most of these mc questions and it's not good when we're just over 12 hours away from the exam!
    Could you help me with 20 and 21 please if you got them? Thanks.
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    Anyone mind explaining Q15 of multiple choice 2014?
    • Welcome Squad
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    (Original post by saad97)
    Tbh I'm like that with most of these mc questions and it's not good when we're just over 12 hours away from the exam!
    Could you help me with 20 and 21 please if you got them? Thanks.
    Tell me about it

    Which paper are those questions from?
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    (Original post by frankiejayx)
    Anyone mind explaining Q15 of multiple choice 2014?
    Post a link to the question pls
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    (Original post by saad97)
    Tbh I'm like that with most of these mc questions and it's not good when we're just over 12 hours away from the exam!
    Could you help me with 20 and 21 please if you got them? Thanks.
    I'm looking for someone to show me how to do them too, absoulte killer paper
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    (Original post by DanielWall96)
    Post a link to the question pls
    http://filestore.aqa.org.uk/subjects...1-QP-JUN14.PDF
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    (Original post by Dante991)
    I'm looking for someone to show me how to do them too, absoulte killer paper
    I'll try help link me the questions
 
 
 
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