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    Q. 23
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  1. File Type: rtf circular motion mixed questions.rtf (1.20 MB, 2004 views)
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    does anyone have a mark scheme for the exam style ques from the text book ?
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    also does anyone have the june 2011 paper and mark scheme ?
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    (Original post by mk207)
    Q. 23
    The answer is D,
    cuz if you equate mw^2r to Bqv,
    according to the question, q=e and m=m obv,
    Using v=wr we can cancel v on both sides.
    So, mw=Be
    then using w=2pi/t
    we get 2pim/T = Be
    rearrange that to make T the subject and there you go!
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    Could somebody explain to me the answer to Q2 June2010
    http://idisk.me.com/mail.matt/Public...W-QP-JUN10.PDF

    I thought i just had to use "ft=mv-mu" but with that i get 100 not 50.
    And Q4 as well thanks
    Thanks
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    (Original post by handsome7654)
    The answer is D,
    cuz if you equate mw^2r to Bqv,
    according to the question, q=e and m=m obv,
    Using v=wr we can cancel v on both sides.
    So, mw=Be
    then using w=2pi/t
    we get 2pim/T = Be
    rearrange that to make T the subject and there you go!
    that's what i did and i got D but my mark scheme says the answer is B... :confused:
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    (Original post by soldiersixteen)
    Could somebody explain to me the answer to Q2 June2010
    http://idisk.me.com/mail.matt/Public...W-QP-JUN10.PDF

    I thought i just had to use "ft=mv-mu" but with that i get 100 not 50.
    And Q4 as well thanks
    Thanks
    You do use the equation Ft = m(v-u)

    Ft = Area = (5000*40)/2 = 100,000

    100,000 = m(v-u)
    100,000 = 2000(v-0)
    50 = v

    I'm not sure about Q4, sorry.
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    (Original post by schizopear)
    that's what i did and i got D but my mark scheme says the answer is B... :confused:
    I've got that question in a booklet made by my college, and the answer in their mark scheme is D. I agree with handsome7654's working, so it must just be a mistake in the mark scheme.
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    (Original post by jones_wise)
    I've got that question in a booklet made by my college, and the answer in their mark scheme is D. I agree with handsome7654's working, so it must just be a mistake in the mark scheme.
    i thought (hoped!) it might be a mistake - thanks
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    How do you do this

    The diagram shows two charges, +4 μC and –16 μC, 120 mm apart. What is the distance from the +4 μC
    charge to the point between the two charges, where the resultant electric potential is zero?
    A) 24mm
    B) 40mm
    C) 80mm
    D) 96mm

    Thanks
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    (Original post by soldiersixteen)
    How do you do this

    The diagram shows two charges, +4 μC and –16 μC, 120 mm apart. What is the distance from the +4 μC
    charge to the point between the two charges, where the resultant electric potential is zero?
    A) 24mm
    B) 40mm
    C) 80mm
    D) 96mm

    Thanks
    you use the electric potential formula

    V=Q/4piepsilon0 x r but the 4piepsilon0 cancels for both so jus ignore it

    so for the 4uC you do V=4uC/120 and for the -16uC you do V=-16uC/120-x

    equate them and solve for x you should get 24mm
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    (Original post by kimmey)
    you use the electric potential formula

    V=Q/4piepsilon0 x r but the 4piepsilon0 cancels for both so jus ignore it

    so for the 4uC you do V=4uC/120 and for the -16uC you do V=-16uC/120-x

    equate them and solve for x you should get 24mm
    Thanks.
    When i equate them, I get
    480u-4ux= -1920u
    -4ux=-2400u
    x=600

    where am i messing up?
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    (Original post by soldiersixteen)
    Thanks.
    When i equate them, I get
    480u-4ux= -1920u
    -4ux=-2400u
    x=600

    where am i messing up?
    Do it like this;
    Cuz the sum of the potentials at a distance x away from 4uC is 0, you get
    +4u/4piepsilon0(x) - 6u/4piepsilon0(20-x) = 0, then add 6u/4piepsilon0(12-x) to both sides,
    4u/x = 6u/120-x (the 4piepsilon0 bit cancels), then multiply by (120-x)
    480u - 4ux = 16ux
    so x = 480u/20u = 24mm!
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    (Original post by mk207)
    Q. 23
    Hi I got the answer of D, is it possible for you to upload a markscheme for these questions if yuo have one? Thanks
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    (Original post by savage903)
    Hi I got the answer of D, is it possible for you to upload a markscheme for these questions if yuo have one? Thanks
    there you go
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  2. File Type: rtf circular motion mixed questions ms.rtf (172.2 KB, 133 views)
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    I have just spent all day printing off every multi choice question from the past 10 years. Highligting the right answer and cutting them out. Then placing them in 7 piles (pile for each topic). After removing recent questions and questions that have already been repeated once I think I can guess a few of out questions, well the ones they will be re-using anyway.
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    can you put them up ???
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    (Original post by maths134)
    I have just spent all day printing off every multi choice question from the past 10 years. Highligting the right answer and cutting them out. Then placing them in 7 piles (pile for each topic). After removing recent questions and questions that have already been repeated once I think I can guess a few of out questions, well the ones they will be re-using anyway.
    could you PM them please to me?
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    (Original post by maths134)
    I have just spent all day printing off every multi choice question from the past 10 years. Highligting the right answer and cutting them out. Then placing them in 7 piles (pile for each topic). After removing recent questions and questions that have already been repeated once I think I can guess a few of out questions, well the ones they will be re-using anyway.
    Can I ask how you got access to all those past papers? If there is a website for them, can u give me the link plzz?? Really need some practice cuz iv only been getting C/Ds on my practice papers!! :mad:
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    If you guys want to spend a day working it out, you welcome to...
 
 
 
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