Join TSR now and get all your revision questions answeredSign up now

AQA A Physics Unit 4 24th Jan 2012 Watch

    Offline

    0
    ReputationRep:
    Q. 23
    Attached Files
  1. File Type: rtf circular motion mixed questions.rtf (1.20 MB, 1864 views)
    Offline

    2
    ReputationRep:
    does anyone have a mark scheme for the exam style ques from the text book ?
    Offline

    2
    ReputationRep:
    also does anyone have the june 2011 paper and mark scheme ?
    Offline

    0
    ReputationRep:
    (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!
    Offline

    0
    ReputationRep:
    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
    • PS Helper
    Offline

    0
    ReputationRep:
    (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:
    Offline

    0
    ReputationRep:
    (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.
    Offline

    0
    ReputationRep:
    (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.
    • PS Helper
    Offline

    0
    ReputationRep:
    (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
    Offline

    0
    ReputationRep:
    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
    Offline

    2
    ReputationRep:
    (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
    Offline

    0
    ReputationRep:
    (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?
    Offline

    0
    ReputationRep:
    (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!
    Offline

    0
    ReputationRep:
    (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
    Offline

    0
    ReputationRep:
    (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
    Attached Files
  2. File Type: rtf circular motion mixed questions ms.rtf (172.2 KB, 123 views)
    Offline

    0
    ReputationRep:
    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.
    Offline

    0
    ReputationRep:
    can you put them up ???
    Offline

    3
    ReputationRep:
    (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?
    Offline

    0
    ReputationRep:
    (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:
    Offline

    0
    ReputationRep:
    If you guys want to spend a day working it out, you welcome to...
 
 
 
Poll
Would you shell out for travel insurance?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.