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How was 9702_12_W15??

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paper was a li'l difficult...however it went well...alhamdulillah
expected GT?

The Sarcastic Retard

Pretty tough at times, but some to half of the questions were rehash past paper questions.. Got 2 wrong so far.. First is the acceleration of the 0.2 kg mass w/ the spring as the 0.1 kg is burned (answer apparently is 5 m s-2, I answered 15 haha).. Second one was dumb.. Was it water waves that demonstrated polarisation? I answered the sound of the thunderclap.. Going back, that was a stupid choice..
 
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Pretty tough at times, but some to half of the questions were rehash past paper questions.. Got 2 wrong so far.. First is the acceleration of the 0.2 kg mass w/ the spring as the 0.1 kg is burned (answer apparently is 5 m s-2, I answered 15 haha).. Second one was dumb.. Was it water waves that demonstrated polarisation? I answered the sound of the thunderclap.. Going back, that was a stupid choice..
I marked waterwaves demonstrating polarised waves...I'm not sure tough... and which question about acceleration??

radioactivity question rate of Alpha decay thing.... was it nucleons at rate 400ms-1?

I made a few dumb mistakes too :p with that diode graph...I marked it filament -_- and uncertainty i was to multiply uncertainty of T*2 ... didn't do that :/ and marked uncertainty as 8% :/
 
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I marked waterwaves demonstrating polarised waves...I'm not sure tough... and which question about acceleration??

radioactivity question rate of Alpha decay thing.... was it nucleons at rate 400ms-1?

I made a few dumb mistakes too :p with that diode graph...I marked it filament -_- and uncertainty i was to multiply uncertainty of T*2 ... didn't do that :/ and marked uncertainty as 8% :/

Yah I checked, that was a past paper question and it WAS nucleons at 400 s-1 luckily. Question was pretty vague, what do you mean material? xD

Supposedly it's the water waves tho, think water waves is the answer because it's the only transverse wave in the question.. Others were stationary.. at the time I said the thunderclap sound because I imagined diffraction occurring in B instead of polarisation, but that clearly was unreasonable reasoning xD
 
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Pretty tough at times, but some to half of the questions were rehash past paper questions.. Got 2 wrong so far.. First is the acceleration of the 0.2 kg mass w/ the spring as the 0.1 kg is burned (answer apparently is 5 m s-2, I answered 15 haha).. Second one was dumb.. Was it water waves that demonstrated polarisation? I answered the sound of the thunderclap.. Going back, that was a stupid choice..
Which question are u talking about of acceleration.
 
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Which question are u talking about of acceleration.
Something involving a 0.2 kg mass attached to a spring with a 0.1 kg mass being attached to the 0.2 kg mass by a thread.. Then the system is let to come to static equilibrium, then thread is burnt.. what is the 0.2 kg mass's upward acceleration at that instant?
 
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Something involving a 0.2 kg mass attached to a spring with a 0.1 kg mass being attached to the 0.2 kg mass by a thread.. Then the system is let to come to static equilibrium, then thread is burnt.. what is the 0.2 kg mass's upward acceleration at that instant?
I did 15 too.. :p
 
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I think the concept to that should be the G.P.E. lost - K.E. gained.. Is the answer B? Or at least somewhere around 1.4 x 10^4-ish? Something like that?

That's one brutal question, like simple F=ma, but just, HOW?! xD
I got A. xD

How do u know 15 is incorrect?? :p
 
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I got A. xD

How do u know 15 is incorrect?? :p
I serched the question.. It was like in an old 1980s CIE paper.. I wish I could say it was 15 m s-2, really xD
Think the concept of the answering was like this..
The moment the 0.1 kg mass snaps, the 3 N tension STILL, at that instant still acts on the spring, and it's now only opposed by a 2 N weight from the 0.2 kg mass only (initially Fnet = 0 as that 3 N tension is opposed by the combined 3 N weights of the 0.1 and 0.2 kg masses), so basically net force is 1 N.

1 N / 0.2 kg = 5 m s-2

Think where we did wrong was in what direction that 1 N force was.. xD
 
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few questions
in the F pushes X and Y
was it B or C?
B said the force exerted by X on Y is equal to F
C said the force exerted by X is less than F
I picked C tbh becuse they're accelerating
also the brass steel, what was the extension??
 
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few questions
in the F pushes X and Y
was it B or C?
B said the force exerted by X on Y is equal to F
C said the force exerted by X is less than F
I picked C tbh becuse they're accelerating
also the brass steel, what was the extension??
I answered C.. not quite sure why but if I draw free body diagrams, I think it's C..
The brass steel I answered B I guess.. 4.0 x 10 to the power of -4 or something like that, I kind of forgot bout that one haha xD
 
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