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    (Original post by Music With Rocks)
    Which textbook is this?

    I would have thought it was 25/1.5^2 = 11.1

    So I don't get that answer either for the corrected count rate
    It's from the 2008 paper
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    (Original post by Alby1234)
    It's from the 2008 paper
    Oh wait,The background count rate is 120 counts per minute

    So therefore corrected count rate at beginning = 25 - 120/60 =23
    Corrected count rate after = 23/1.5^2 = 10.22...
    Corrected count rate + background count = 10.22,,, +120/60 = 12.2 (3sf)
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    How do I do (b) and (c)? Topic 2.3 Turning points (OPTION D)

    2. When a metal surface is illuminated with light of wavelength 410 nm, photoelectrons are emitted with amaximum kinetic energy of 2.10 × 10−19 J.Calculate:
    a the energy of a photon of this wavelength
    b the work function of the metal surface
    c the stopping potential for this surface illuminated by light of wavelength 410 nm

    So for part
    (a) E=hc/lambda =(6.63*10^-34)*(3*10^8)/410*10^-9
    E=4.85*10^-19 j

    then I thought
    (b) work function = hf - Ek
    =4.85*10^-19 - 2.10*10^-19
    = 2.75*10^-19

    but this is wrong textbook answer is 1.61*10^-19j

    What am I doing wrong?
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    Anyone got a table of grade boundaries?
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    Anyone else here absolutely despise Astrophysics 😂😂
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    What's the range of an alpha particle and beta in a vacuum?
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    (Original post by Nikhilm)
    What's the range of an alpha particle and beta in a vacuum?
    Infinite
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    (Original post by Nikulp68)
    Infinite
    and beyond?
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    Name:  ImageUploadedByStudent Room1466442847.723250.jpg
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    Can anyone explain why for 1bii they've ignored the neutrons completely in the MS?


    Posted from TSR Mobile
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    They don't have any binding energy, so they can be ignored.
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    lack of past papers for this exam is sooooooooo irritating
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    Watching
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    (Original post by WillRose)
    lack of past papers for this exam is sooooooooo irritating
    Have a look at old spec papers mate. Unit 8 is the name of one of the papers: It has Nuclear Radioactivity and the second part of the paper is the optional unit that we have now


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    (Original post by Yo12345)
    Have a look at old spec papers mate. Unit 8 is the name of one of the papers: It has Nuclear Radioactivity and the second part of the paper is the optional unit that we have now


    Posted from TSR Mobile
    ah okay? where can i find them, do you have any links? thanks
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    (Original post by WillRose)
    ah okay? where can i find them, do you have any links? thanks
    http://theallpapers.com/assessment-a...iance/a-level/

    Click Physics A on the menu.
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    (Original post by WillRose)
    ah okay? where can i find them, do you have any links? thanks
    They are on the AQA website I think. Older past papers or something along those lines


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    Anyone doing medical?
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    Boundaries are like 53/54 (excluding 2015) for an A* .....why?

    Turning points is usually higher though
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    (Original post by particlestudent)
    Boundaries are like 53/54 (excluding 2015) for an A* .....why?

    Turning points is usually higher though
    I think because some people can already tell what they need / its the last exam for most people / no multiple choice / different sections
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    Alright so who else has a **** of a teacher that made them do turning points?
 
 
 
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