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    Can someone please explain this to me?
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    (Original post by Rahatara Sadique)
    Yes, I have checked the marking scheme again and it says C.
    But mean square speed is proportional to temperature...
    I have understood why it is C.

    The question says mean SQUARED speed has doubled, and as it is proportional to temperature, temperature doubles as well. So it is C.

    In other cases for instance if we say the VELOCITY has doubled so by what factor kinetic energy changes, it will increase by a factor of 4 as the formula says EK= a=0.5mv^2 and the question asks about velocity over here, not v^2

    Coming back to the main question in the question paper, it has already been mentioned that they are referring to <c>^2, not c alone....so answer is C.

    Hope the explanation is correct.
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    (Original post by apocolyptic)
    Attachment 557383can someone explain this to me please?
    mountain top: r = 1.0006r

    mountain bottom: r = r

    F is proportional to 1/r^2

    1 - 1 = -0.001189
    (1.0006)^2

    -0.00189*100 = -1.2%
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    Jan 2016 IAL Q10 please!
    Attached Images
  1. File Type: pdf January 2016 (IAL) QP - Unit 5 Edexcel Physics - Copy.pdf (665.8 KB, 76 views)
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    About 25% of the mass of our Universe is thought to consist of dark matter. A keyproperty of dark matter is that it
    A absorbs all electromagnetic-radiation.
    B cannot be detected.
    C emits no detectable electromagnetic-radiation.
    D exerts no gravitational force.

    I thought A, but it's C? How come.
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    Why is lambda 2l and not just l?
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    (Original post by Rahatara Sadique)
    Jan 2016 IAL Q10 please!
    I got C. Do you have the mark scheme for this paper?
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    (Original post by 16characterlimit)
    About 25% of the mass of our Universe is thought to consist of dark matter. A key property of dark matter is that it
    A absorbs all electromagnetic-radiation.
    B cannot be detected.
    C emits no detectable electromagnetic-radiation.
    D exerts no gravitational force.

    I thought A, but it's C? How come.
    A key property of dark matter is that it doesn't absorb, reflect or emit electromagnetic radiation
    The answer could technically be B or C
    but C is more important i guess so that's the answer
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    (Original post by the-anonymous-me)
    Name:  Screen Shot 2016-06-27 at 22.21.35.png
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    Can someone please explain this to me?
    in a mass spring system, time period is dependent on the spring constant and mass. These have not changed so the frequency is the same
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    (Original post by target21859)
    Why is lambda 2l and not just l?
    Because here l is the distance between a peak and trough - lambda is the distance between two peaks or two troughs so 2l
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    (Original post by orderfuture)
    in a mass spring system, time period is dependent on the spring constant and mass. These have not changed so the frequency is the same
    Thanks x

    (Original post by mrbeady9)
    I got C. Do you have the mark scheme for this paper?
    Here's the link to the google drive with all the January 2016 papers and mark schemes:

    https://drive.google.com/folderview?...nR2ZW5PcGhLQWM

    The answer is c
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    (Original post by mrbeady9)
    I got C. Do you have the mark scheme for this paper?
    Just found the mark scheme. It is C. They give you the graph for acceleration which is a sinx graph. Therefore to find velocity you integrate once giving you -cosx.

    To differentiate: (Integration is just the reverse)
    Sinx
    v
    Cosx
    v
    -Sinx
    v
    -Cosx
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    (Original post by the-anonymous-me)
    A key property of dark matter is that it doesn't absorb, reflect or emit electromagnetic radiation
    The answer could technically be B or C
    but C is more important i guess so that's the answer
    The answer is C because technically you can detect dark matter as we know it exists. I know it's a weird explanation, but hey, it's Edexcel.
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    (Original post by mrbeady9)
    The answer is C because technically you can detect dark matter as we know it exists. I know it's a weird explanation, but hey, it's Edexcel.
    Thanks - I hate the multiple choice questions - Edexcel always has the odd question where it's kind of vague about what the right answer could be
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    June 2012 q 19 c I've PLEASE!
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    why is the answer to this d and not c?
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    What is everyone's plan going into tomorrow exam?

    I've recapped the theory and going to review all past papers I've done from Edexcel + IAL
    from 12:00am-6:30am and then go to my exam.

    Note: I slept during the day.
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    (Original post by Rahatara Sadique)
    June 2012 q 19 c I've PLEASE!
    I hope you're still awake to see this, although you should probably sleep soon, like me. I'm assuming your problem with 19(c)(iv). This is a difficult question. I didn't understand it for a long time after multiple attempts. My working out is attached, I know it's very rough, but I just kind of winged it.
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    (Original post by XxKingSniprxX)
    What is everyone's plan going into tomorrow exam?

    I've recapped the theory and going to review all past papers I've done from Edexcel + IAL
    from 12:00am-6:30am and then go to my exam.

    Note: I slept during the day.
    Very odd technique but goodluck!
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    I reckon differences and similarities between electric and gravitational fields will come up!
 
 
 
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