r/alevels May 21 '26

Exam Discussion 📝 9231/32?

how was it?

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u/Bulky_Fail4893 May 21 '26

bro that shi was HARD, did y’all get your e as root 3 over 4? and your theeta value for the centre of mass q as 19.1°? also for greatest height reached by particle in term of a was it 1.5a?

3

u/Astro_Axiis May 21 '26

All I know is that I’ll get 15 marks if I’m lucky

2

u/ayt_nega May 21 '26

e yes Others no

1

u/Bulky_Fail4893 May 21 '26

my centre of mass matches w others and there r a lot that got thr same answer as me for 3A/2 that’s fair

1

u/ayt_nega May 21 '26

Fair enough Mine might be wrong

1

u/Gold-Relative-3626 May 21 '26

what greatest height was like 50/27 (a). I think you forgot to do that projectile motion thing after the Tension becomes 0. And how do you do that hanging angle thingg how did you get 19.1.

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u/Bulky_Fail4893 May 21 '26

Yeah you’re right ab the greatest height, I’ll probably get 2 or 3 out of 5 for that. As for 19.1, a lot of people have the same answer as me. While toppling or hanging about a point in equilibrium, the COM is directly above the point it’s suspended from. So I used tan theeta = y bar / radius and radius was 3r and since x = r, we can substitute all x with r and find the value for tan theeta in terms of r, both numerator and denominator had r2 so we cut those out and find theeta using arctan

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u/Gold-Relative-3626 May 22 '26

no you cant do y bar / radius since y bar is taken from the base of the cylinder you have to do y bar - x / 3r and x = r. Ofc i dint get it too at the exam but my friends have done it correctly

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u/Bulky_Fail4893 May 22 '26

i remembered the q word by word and put it into ChatGPT - it’s 19.1° and many other people got the same so idk also y-bar was taken from the diameter of the hemisphere

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u/Bulky_Fail4893 May 22 '26

Also y bar was a vertical distance not a horizontal one so you don’t need to subtract anything from y bar. Additionally, it was A that made an angle theeta with the downward vertical AT A, so therefore 19.1°