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    how did everyone find it I thoguht it was quite easy,except the last question.
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    Yeh i thought it was ok, last question was rather tricky tho...

    What did everyone get as the ratio in that question?

    I got nearly exactly 2Pi = 6.289 ish
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    (Original post by Laffo)
    Yeh i thought it was ok, last question was rather tricky tho...

    What did everyone get as the ratio in that question?

    I got nearly exactly 2Pi = 6.289 ish
    ratio, what ratio :eek:
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    De Brogile and Circumference Ratio. I got 1.
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    Hurrah! I got the ratio as 1 too.
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    (Original post by Dogberry)
    De Brogile and Circumference Ratio. I got 1.
    don't remember that at all :confused: What did people get for the density question i kept getting 8000,which seemed to big but i left it in the end, and for l0 i got about -317mm, g=10.1,efficeincy 11%,critical angle 13ish, the rest were a bit of a blurr i just remmber them beign quite straight forward, i only ever remember the tricky bits.
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    (Original post by marisad_uk)
    don't remember that at all :confused: What did people get for the density question i kept getting 8000,which seemed to big but i left it in the end, and for l0 i got about -317mm, g=10.1,efficeincy 11%,critical angle 13ish, the rest were a bit of a blurr i just remmber them beign quite straight forward, i only ever remember the tricky bits.
    All sound bout right from what I can remember
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    (Original post by deity47)
    All sound bout right from what I can remember
    just had a thought though how can the original length be -317 lengths cant be minus numbers oh well that graph was a bit wonky and i figured it out using long p1 maths :rofl:
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    It was ok.

    Some questions, especially on the last page, seemed like you had to do loads of steps within each little question. Did anyone get the speed of the electron to be something * 10-4 ms-1? First I wasn't sure how it could be so slow, but then realised that it's travelling round such an incredibly miniscule distance.

    I messed up the graph somehow. I got g to be 10.2, which isn't too far off, so I can't have been all wrong, but I got some stupid negative answer for the original length.

    Also, wasn't sure how we were meant to show that some oxygen would escape the moon. I worked out the average kinetic energy would be less than the potential energy.
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    (Original post by mr_shoe_uk)
    Also, wasn't sure how we were meant to show that some oxygen would escape the moon. I worked out the average kinetic energy would be less than the potential energy.
    Me too, but it is simply that the whilst the mean kinetic energy is smaller than the potential energy, some oxygen atoms wil be emitted with kinetic energy much greater than the mean, and these are the ones that will escape.. I think/hope
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    (Original post by mr_shoe_uk)
    It was ok.

    Some questions, especially on the last page, seemed like you had to do loads of steps within each little question. Did anyone get the speed of the electron to be something * 10-4 ms-1? First I wasn't sure how it could be so slow, but then realised that it's travelling round such an incredibly miniscule distance.

    I messed up the graph somehow. I got g to be 10.2, which isn't too far off, so I can't have been all wrong, but I got some stupid negative answer for the original length.

    Also, wasn't sure how we were meant to show that some oxygen would escape the moon. I worked out the average kinetic energy would be less than the potential energy.
    i didnt get the oxygen thing either because it gave us the two energy values and then asked how it could escape, i made soemthing up about not haivng enouh mass to be attracted all the way to the surface, or the odd particle might have loads of energy and be able to escape! I got something really slow for speed of the electron and thought it was probably wrong as well. did u use mv^2/r=Q1Q2/4πE0r?
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    for electron speed i got 2.2 x 10^6 m/s

    i thought the exam went really well but then afterwards my friends were talking about a ratio question. i didnt remember it AT ALL.. so i missed a god damned question out :mad: :mad: :mad:
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    (Original post by marisad_uk)
    i didnt get the oxygen thing either because it gave us the two energy values and then asked how it could escape, i made soemthing up about not haivng enouh mass to be attracted all the way to the surface, or the odd particle might have loads of energy and be able to escape! I got something really slow for speed of the electron and thought it was probably wrong as well. did u use mv^2/r=Q1Q2/4πE0r?
    Kinda did the same for oxygen escaping the moon, said the kinetic energy is only an average, so some may have enough energy to escape the surface.

    For the electron speed I pretty much used that equation too. Didn't write it out as that, I just said that the force of attraction worked out earlier = centripetal force (actually wrote in words), so a = F/m, then used a circular motion formula, think it was a = v2/r

    When you think about how absolutely tiny the circumference of the orbit was, 10-4 ms-1 still means it is whizzing round many times a second, so I think/hope we may have been right
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    (Original post by xelprep)
    for electron speed i got 2.2 x 10^6 m/s

    i thought the exam went really well but then afterwards my friends were talking about a ratio question. i didnt remember it AT ALL.. so i missed a god damned question out :mad: :mad: :mad:
    It was on the last question, about De Broglie wavelength. A few people here say it was 1, wheras I got a thousand or something.. so I think I got it wrong. Hopefully I didn't get previous questions needed for it wrong too.
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    Was a pretty good paper - didn't find it to bad.

    As for that last question.. the one about oxygen leaving the planet, I said there would be a surplus of energy after heating it to 400K, so the remaining energy would result in there being KE and therefore motion, which would let it escape into space.

    Or something to that affect.

    MdSalih
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    it was a bit pants i thought
    I had a blank and totally forgot Hookes law HOOKES LAW! the godamn easiest little thing to remember! grrrrr....
    What ya'll think the A grade percentage will b? 70%?
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    for electron speed i got something about c/10. whatever it was i remember looking at it and thinking "yeah why not". the rest was ok - left the graph til last and had 30mins for it (i fell out with graphs in the physics practical exam, not been the same since) and was chuffed that i somehow manaed to get g=9.75 (9.8 to 2sf ) and then got a round figure for lo
    nice little gcse question to easeinto the paper as well - distance = speed/time. even remembered to halve the distance for the full 3 marks
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    (Original post by corkskrew)
    nice little gcse question to easeinto the paper as well - distance = speed/time. even remembered to halve the distance for the full 3 marks
    Distance = speed x time I'm sure you meant :p:
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    (Original post by corkskrew)
    for electron speed i got something about c/10. whatever it was i remember looking at it and thinking "yeah why not". the rest was ok - left the graph til last and had 30mins for it (i fell out with graphs in the physics practical exam, not been the same since) and was chuffed that i somehow manaed to get g=9.75 (9.8 to 2sf ) and then got a round figure for lo
    nice little gcse question to easeinto the paper as well - distance = speed/time. even remembered to halve the distance for the full 3 marks
    Yeah, that question about the sonar was quite nice.

    The very opening question was one of those with loads of steps though. First you needed to use the potential energy formula, then know what power is work done divided by time taken, then work out the electrical power supplied, then do the efficiency as power out/power in! They could have made a whole question out of that, instead it was a tiny part! ..I think it was 11.1%?
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    (Original post by lessthanthree)
    I think I got a C.
    i'm glad sum1 feels as crap as me

    what happened?
 
 
 
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