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    Has someone done a hitler video yet ?

    I feel like doing one
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    (Original post by tomhiggins7)
    yeah i put the initial gradient as the same, but said the the acceleration would continue increasing for a longer period, and my sketch on the graph had the same initial gradient and stayed steeper than the other gradient for longer, until it reached a constant velocity, a bit higher up than the lorry without the leak.
    Didn't it say that the water will leak out during all the time shown on the graph?
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    (Original post by Nerrad)
    It said you can draw ON the graph, not draw a graph haha. So I drew a dotted line between when the gradient is increasing and when the gradient is 0. Then labelled resistive force=driving force and resistive force < driving force. Hope I'm right
    Yeah i just drew another curve on the graph
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    (Original post by mbh16)
    Yeah i just drew another curve on the graph
    What did yours look like?
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    Here are some numerical answers I got in the order they were in the exam, no idea if they are correct:

    (Bear in mind I didn't have time to save the x10^x for the numbers - very rushed exam!)

    196
    361 < (moment of weight)
    11
    1.3
    14
    0.206
    2.86
    3.32
    0.18
    1.8
    0.6
    0.058
    23
    1.32
    no,yes,yes,no (the sound waves thing, dunno if its right)
    17
    3
    24.4
    18.5
    19
    8.4
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    (Original post by thatcooldude2.0)
    What did yours look like?
    Same as the first but with a slightly steeper gradient and a higher plateau after a longer time

    did everyone get 3 for the number of diffraction angles? I hate those questions.
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    (Original post by Rahmada)
    The embankment one:

    R (Reaction force at embankment) = 0
    Resolve from the rock.
    Vertical force at the left much be greater than the right for the boy to stand without falling

    Mass of boy = 46kg Distance to boy = 0.8
    Mass of plank = 40kg Distance to C.O.M = 1.2

    46g * 0.8 = 40g * 1.2 + C
    313.6 = 361 + C
    C is negative so the boy can stand.

    That's how I did it.
    If you're doing it from the bank you need the support force of the rock which would be 86g I think?
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    i Think alot of people in this thread are forgetting that for the 6 mark question, The initial Acceleration at t= 0 will be the same as the one that is not leaking because the mass is the same as no water has leaked out already. I also mentioned that Force = Coefficient of friction x reaction force and that reaction force = weight so therefore the Force is dependant on the mass of the truck so the maximum frictional force will be less because of the smaller mass, this will lead to a greater velocity reached.

    For the Diamond question , i said that the material which had a greater refractive index would have a smaller refractive index and therefore there is a higher probability of angle of incidence being greater than the critical angle which would lead to more total internal reflection
    • Welcome Squad
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    Welcome Squad
    So depressed now.
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    How many points was the diamond drawing? I didnt have time so skipped it
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    My curve was steeper gradient, reaching terminal velocity earlier and a higher terminal velocity than the other.
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    (Original post by thatcooldude2.0)
    What did yours look like?
    Name:  Screen Shot 2016-06-09 at 16.19.52.png
Views: 44
Size:  7.8 KB

    A bit like this but then flattened it off
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    Yes at the start the gradient is the same... At 0... But as soon as it leaves rhe origin the gradient will be steeper as water has leaked?
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    (Original post by thatcooldude2.0)
    What did you guys get for the max vertical height in the projectile motion question?
    1.3 i think

    using u=5
    a=-9.81
    v = 0
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    (Original post by WashingPowder)
    i Think alot of people in this thread are forgetting that for the 6 mark question, The initial Acceleration at t= 0 will be the same as the one that is not leaking because the mass is the same as no water has leaked out already. I also mentioned that Force = Coefficient of friction x reaction force and that reaction force = weight so therefore the Force is dependant on the mass of the truck so the maximum frictional force will be less because of the smaller mass, this will lead to a greater velocity reached.
    Yeah your correct....i out the greater velocity but didnt catch the gradient part.....you think maybe dropped 2 marks for that?
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    (Original post by clarkey500)
    If you're doing it from the bank you need the support force of the rock which would be 86g I think?
    I resolved from the rock so you can ignore all the forces through it,.
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    (Original post by Nerrad)
    Did anyone get 2.9ms^-1 for the rocket question which means that the engine will manage to decelerate to the safe speed?
    yes
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    (Original post by micycle)
    This is how I drew it:

    Damn i did this first time but then I dooubted if the ray entered the diamond vertically or horizontally so I did it differently in the end
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    (Original post by Rahmada)
    I resolved from the rock so you can ignore all the forces through it,.
    Oops! misread what you put! I resolved from the rock and found that he could walk without it tipping!
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    (Original post by Ben_Clare)
    yes
    i messed this one up because i said that the forces were not the same and that it would not slow it down safely
 
 
 
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