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

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    Maybe it's to do with the fact they're in equilibrium

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    (Original post by Jimmy20002012)
    Electric field line always act from positive to negative, so if the electric field in upwards the particle must have a negative charge. I think this is why, but not 100% sure.
    (Original post by huniibehi)
    I know that's what I thought! But no diagram so I don't get why it would be positive

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    Oh I see sorry, I misread the question in the first place -,-

    Here's what the question is saying:
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    Oh right thanks!! One more thing, could you lend me your brain for this exam?

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    (Original post by huniibehi)
    Oh right thanks!! One more thing, could you lend me your brain for this exam?

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    😂 would if I could... But that would leave me not only failing physics but kind of a little... Lifeless


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    I suppose you could have my brain, that way you wouldn't be lifeless although you'd still fail physics :awesome:

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    (Original post by huniibehi)
    I suppose you could have my brain, that way you wouldn't be lifeless although you'd still fail physics :awesome:

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    Oh come on. Positivity! (Insert pun about electric fields).


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    (Original post by CD223)
    Question 10:
    The answer is B.

    This is because resonance curves show that a system reaches maximum amplitude (a sharp resonance peak) when the driving frequency equals the natural frequency if the damping is light.

    Attachment 410715

    When a system is damped more and more, the amplitude at resonance is reduced and moreover, the resonant frequency is slightly reduced.


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    You're a babe! Thank you so much - I'll have a read now
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    (Original post by aprocrastinator)
    You're a babe! Thank you so much - I'll have a read now
    No problem haha! Just hope it helps


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    (Original post by CD223)
    No problem haha! Just hope it helps


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    It's great thank you! Just one question - I think I'm being really thick but how do you derive 2Em square root to be the momentum from the kinetic energy equation?
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    anyone have an easy way of getting their head around fields?? ha ha ha
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    (Original post by aprocrastinator)
    It's great thank you! Just one question - I think I'm being really thick but how do you derive 2Em square root to be the momentum from the kinetic energy equation?
    Does this help?

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    (Original post by oonic0rn)
    anyone have an easy way of getting their head around fields?? ha ha ha
    Which aspects?


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    Doing more than 3 of these 1:45 mins papers per day is brutal lol


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    (Original post by CD223)
    Anyone care to explain why sharp points produce intense fields?

    Is it something to do with:
    

E = \dfrac{\Delta V}{\Delta d}

    Where there is a large potential across a small distance?


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    Words won't suffice the reason as to why sharp points produce intense electric fields and I'm not sure about the answer but experimental observations suggest that electric field strength is proportional to charge density, that is charge per unit area. The theoretical understanding of it can seemingly be achieved by Gauss's Law.


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    (Original post by CD223)
    Which aspects?


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    i just cant get my head around them, i dont even know what i dont know

    the whole of unit 4 is driving me crazy!!!
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    (Original post by Mehrdad jafari)
    Doing more than 3 of these 1:45 mins papers per day is brutal lol


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    Ouch! 3 PHYA4 papers? Or?

    (Original post by Mehrdad jafari)
    Words won't suffice the reason as to why sharp points produce intense electric fields and I'm not sure about the answer but experimental observations suggest that electric field strength is proportional to charge density, that is charge per unit area. The theoretical understanding of it can seemingly be achieved by Gauss's Law.

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    Ah! Thank you! Given that it's something we don't need to know, I'm hoping there won't be a question on it aha!


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    (Original post by oonic0rn)
    i just cant get my head around them, i dont even know what i dont know

    the whole of unit 4 is driving me crazy!!!
    Ironically, I prefer unit 4 to unit 5! What option do you do?


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    (Original post by CD223)
    Ouch! 3 PHYA4 papers? Or?



    Ah! Thank you! Given that it's something we don't need to know, I'm hoping there won't be a question on it aha!


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    Yeah, or even the chemistry ones are just horrible.


    Hopefully not, but always the examiners find something simple and make it so complicated that cannot be considered physics anymore lol


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    (Original post by Mehrdad jafari)
    Yeah, or even the chemistry ones are just horrible.


    Hopefully not, but always the examiners find something simple and make it so complicated that cannot be considered physics anymore lol


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    That's very true. Seems it's impossible to understand the simplest concepts in papers these days -.-


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