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Most probable speed

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AQA GCSE physics P1 unofficial mark scheme 05-05-2016
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    For a Nitrogen molecule I'm using the equation:


    The temp is at 500k and the boltzmann constant is obviously a constant value but I'm not sure what the m is, is it the molar mass in kg (if so I get a ridiculously small value for the speed) or is it the mass of one particle of N2 so 28 x10^-3 x (avogadro's constant) ??? But then I get a really big value which seems too large to be true

    EDIT: Also have a question about calculating the rms speed of free electrons in the sun's atmosphere. Though it gives me a value for the pressure so can I not just use the Vrms equation = sqrt(3KbT/m)???

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    Anyone? :P
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    It is the mass of one nitrogen molecule. This can be approximated to 28amu ( total number of protons and neutrons x the atomic mass unit (~ 1.66x10^-27kg)).

    It should be rather large , they do move fairly quick!

    As for your edit I think the problem with using that equation lies with knowing the temperature, which I suspect you're not given. Do you know a relation between pressure and temperature?


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