# OCR M3 (non MEI) Wednesday 8th JuneWatch

Announcements
3 years ago
#61
Hitler Reacts:
3
3 years ago
#62
This is brilliant, haha, put a smile on my face after a sh**ty exam
0
3 years ago
#63
(Original post by Muzzles)
This is brilliant, haha, put a smile on my face after a sh**ty exam
Thanks both Mechanics exams dreadful as well! :'(
0
3 years ago
#64
Terrific Hitler reacts ahahah
0
3 years ago
#65
How many people are doing M4? After a difficult M2 and M3 I can't wait to see what stuff they'll throw into the M4 this year ahaha!

Also was w^2=98 and A=0.675 for the last question?
0
3 years ago
#66
Well I got w^2=392 and A =0.225

w^2 = L/l = 24mg/0.6 = 392
0
3 years ago
#67
(Original post by Miracle-)
Well I got w^2=392 and A =0.225

w^2 = L/l = 24mg/0.6 = 392
Oh, I did (4m)a=4mg-24mg(0.1+x)/0.6
And so a=-392x/4 and so w^2=98.
Then 2.1^2=98(A^2-0.075^2), A=0.675. No idea if it's right, hopefully some method marks even if I'm wrong
1
3 years ago
#68
(Original post by JoeyTr)
Oh, I did (4m)a=4mg-24mg(0.1-x)/0.6
And so a=-392x/4 and so w^2=98.
Then 2.1^2=98(A^2-0.075^2), A=0.675. No idea if it's right, hopefully some method marks even if I'm wrong
0
3 years ago
#69
(Original post by JoeyTr)
How many people are doing M4? After a difficult M2 and M3 I can't wait to see what stuff they'll throw into the M4 this year ahaha!

Also was w^2=98 and A=0.675 for the last question?
That's what I got yeah, not sure what my a was though

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0
3 years ago
#70
(Original post by JoeyTr)
Oh, I did (4m)a=4mg-24mg(0.1+x)/0.6
And so a=-392x/4 and so w^2=98.
Then 2.1^2=98(A^2-0.075^2), A=0.675. No idea if it's right, hopefully some method marks even if I'm wrong
I agree with w^2=98 but doesn't the equation you wrote give A=0.225? Also do you remember what you got for the time for the last part of Q7?
0
3 years ago
#71
(Original post by JoeyTr)
Oh, I did (4m)a=4mg-24mg(0.1+x)/0.6And so a=-392x/4 and so w^2=98.Then 2.1^2=98(A^2-0.075^2), A=0.675. No idea if it's right, hopefully some method marks even if I'm wrong
Wait using your w I still get A=0.225In fact 2.1^2 = 98(0.225^2-0.075^2)

so w^2 = 98 a=0.225
0
3 years ago
#72
Time I got 0.796 u?
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3 years ago
#73
allow that last question
0
3 years ago
#74
(Original post by Miracle-)
Time I got 0.796 u?
0.888 seconds, what was your method?
0
3 years ago
#75
anyone remember the jist of each of the first 5 questions? like which was the impulse one, which was the particle on a string going in a circle, which was the collision question, which was the one with resistive force of (1/8)x or something... and what were the others? (of the first 5 only, know the last 2)
thanks.
0
3 years ago
#76
(Original post by Muzzles)
0.888 seconds, what was your method?

2/7 seconds from suvat. t = root(0.8/9.8)

3/4 of a period so 3/4 * 2pi/root98 = 0.476 s

the first bit from 0.075 above to 0 = sin-1(0.075/0.225)/root98 = 0.034s

most likely something wrong, how did you do it?
0
3 years ago
#77
(Original post by Miracle-)
Wait using your w I still get A=0.225In fact 2.1^2 = 98(0.225^2-0.075^2)

so w^2 = 98 a=0.225
Oh yeah, deary me, must've divided by 9.8 instead of 98!
0
3 years ago
#78
(Original post by Muzzles)
I agree with w^2=98 but doesn't the equation you wrote give A=0.225? Also do you remember what you got for the time for the last part of Q7?
Didn't get a time, other than the suvat 2/7 bit. Just w^2 and my wrong amplitude! Probably like 2 marks out of 7
0
3 years ago
#79
(Original post by JoeyTr)
Didn't get a time, other than the suvat 2/7 bit. Just w^2 and my wrong amplitude! Probably like 2 marks out of 7
do you remember what question 2 and 3 were on?
0
3 years ago
#80
(Original post by Simonium1010)
do you remember what question 2 and 3 were on?
One of the was the linear motion with variable forces question, the other was either impact question or SHM question

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