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    (Original post by philo-jitsu)
    Yeah thats right, when you say why...what do you mean? Do you mean why is that angle theta, or why do we use that line?
    Thanks, both i think, sorry, I just don't get on the equation lambda=dsintheta what the angle is measuring and where it is taken from.
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    (Original post by ryandaniels2015)
    Thanks, both i think, sorry, I just don't get on the equation lambda=dsintheta what the angle is measuring and where it is taken from.
    Awww, okay so the original angle theta which is on the diagram is the angle between a line perpendicular to the grating (straight through the grating) and then to the first (or in this case 2nd) order which is the 2nd bright fringe from the central fringe (zero order).

    There is more explanation as to why this now can be used to fit the formula lambda=dsintheta but you wont need it for this.

    Let me know if this doesnt clear it up
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    (Original post by philo-jitsu)
    Awww, okay so the original angle theta which is on the diagram is the angle between a line perpendicular to the grating (straight through the grating) and then to the first (or in this case 2nd) order which is the 2nd bright fringe from the central fringe (zero order).

    There is more explanation as to why this now can be used to fit the formula lambda=dsintheta but you wont need it for this.

    Let me know if this doesnt clear it up
    Thanks for the reply, so why when I guessed where the angle went in my diagram does it go there?
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    and we draw the dotted line because it makes composing the triangles for the equations easier, we could still use the line with the actual theta drawn on the diagram but it makes it slightly more difficult, so the angle is just flipped 90 degrees so it still works ....its difficult to explain without drawing out huygens stuff but just knowing where the angles come from should be more than enough for unit 2

    Also just for curiosity is medical physics interesting?, I'm doing biology as well and keep thinking they aren't going into enough detail on topics, I figure medical physics would go into greater detail.
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    (Original post by ryandaniels2015)
    Thanks for the reply, so why when I guessed where the angle went in my diagram does it go there?
    The angle doesnt really go there, the angle is put there because the diagram chooses to form the triangle for the lambda equation in the location, it would work using the top theta but then they would have to draw out where 'd' is along the perpendicular dotted lines, all they do is flip the line 90 degrees so they can use the 'd' which is already on the diagram.

    The dotted line which is perpendicular to the dotted line doesnt need to be there at all its just a quicker way of drawing the diagram
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    (Original post by philo-jitsu)
    and we draw the dotted line because it makes composing the triangles for the equations easier, we could still use the line with the actual theta drawn on the diagram but it makes it slightly more difficult, so the angle is just flipped 90 degrees so it still works ....its difficult to explain without drawing out huygens stuff but just knowing where the angles come from should be more than enough for unit 2

    Also just for curiosity is medical physics interesting?, I'm doing biology as well and keep thinking they aren't going into enough detail on topics, I figure medical physics would go into greater detail.
    Medical physics is good if you like to go into the details of hearing, eyes, X-rays, etc more based on regurgitating information rather than solving problems though.
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    Thanks for the help, still slightly confused but it's getting there...
    (Original post by philo-jitsu)
    The angle doesnt really go there, the angle is put there because the diagram chooses to form the triangle for the lambda equation in the location, it would work using the top theta but then they would have to draw out where 'd' is along the perpendicular dotted lines, all they do is flip the line 90 degrees so they can use the 'd' which is already on the diagram.

    The dotted line which is perpendicular to the dotted line doesnt need to be there at all its just a quicker way of drawing the diagram
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    (Original post by ryandaniels2015)
    Thanks for the help, still slightly confused but it's getting there...
    Thats physics, just when you think you understand it you find something thats wrong with your idea...its maddening lol, but like I said its much easier to grasp when you have all the parts (huygens) but taking the time to learn that when your not tested wouldnt be too smart this close to exams.

    But definately just draw out the lines, including the patterns they cause on the screen and it eventually comes to you
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    (Original post by philo-jitsu)
    Thats physics, just when you think you understand it you find something thats wrong with your idea...its maddening lol, but like I said its much easier to grasp when you have all the parts (huygens) but taking the time to learn that when your not tested wouldnt be too smart this close to exams.

    But definately just draw out the lines, including the patterns they cause on the screen and it eventually comes to you
    Yh will do thanks for the help!
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    I was wondering, with all the 6 markers that have been asked, if you learn them, should you be ok? Or could they ask something new?
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    (Original post by boyyo)
    wait, so further maths D1 is different to normal maths d1?
    nope, it's the exact same i believe, as it can be switched between maths and further. i do OCR MEI tho
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    (Original post by Music With Rocks)
    I am guessing you have had no luck? haha
    I got in touch with him but he said he doesn't have the files anymore because they were saved on his school login or something and when you leave, they all disappear basically so they're gone :/
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    (Original post by Stallzy)
    nope, it's the exact same i believe, as it can be switched between maths and further. i do OCR MEI tho
    I do OCR MEI! I know this isn't the maths thread but do you have any tips for someone who can't do C3 to save their lives? I got 15 on the coursework but I cant seem to get above an E on any past papers...
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    (Original post by Stallzy)
    nope, it's the exact same i believe, as it can be switched between maths and further. i do OCR MEI tho
    ahh man I had the same board when I did as further maths, they suck lol
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    In questions 2a(i) here;
    https://5505b400f275fd9f29b9b4679ca5...%20Physics.pdf

    can anyone explain why you cant used s=ut + 0.5at^2 ?

    Also is s=0.5(u+v)t a suvat equation? What i mean by this is thatt; I have been taught to only use suvat equations when accelartion=0 and velocity is changing. In a question I did earlier, it asked for the average acceleration and I had to use v^2=u^2 + 2as. How come I could use this eqation, as accelaeration is not constant?
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    (Original post by boyyo)
    In questions 2a(i) here;
    https://5505b400f275fd9f29b9b4679ca5...%20Physics.pdf

    can anyone explain why you cant used s=ut + 0.5at^2 ?
    You would need to use s = 0.5(u+v)t ,where s = 50 u = 0 and v = 6.7
    you cant use that equation as you don't have the value for acceleration
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    (Original post by sorch1)
    You would need to use s = 0.5(u+v)t ,where s = 50 u = 0 and v = 6.7
    you cant use that equation as you don't have the value for acceleration
    ahh ok thanks
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    Did anyone else find the June 2010 paper near impossible?
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    (Original post by McDerdactyl)
    Did anyone else find the June 2010 paper near impossible?
    It was tricky...the diffraction spectra was one ive never seen before...but after looking at the answer it actually makes perfect sense...the trampoline section was easy to mess up on...but the grade boundaries did match the difficulty.
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    (Original post by McDerdactyl)
    I got in touch with him but he said he doesn't have the files anymore because they were saved on his school login or something and when you leave, they all disappear basically so they're gone :/
    That is unfortunate :/, thank you for the update anyway
 
 
 
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