You are Here: Home >< Maths

OCR M3 (non MEI) Wednesday 8th June Watch

1. (Original post by bred123)
woudnt the last question involve a phase shift, so a extra constant in the sin bracket since it didnt start at the extreme extension?

i got the amp and other things wrong so il only get about 6 marks total for last question but im pretty sure you needed a phase shift,and im pretty sure it was the first time its ever came up on ocr
It came up recently 14 I think, component falls under gravity plus shm stuff if that's what you meant by phase shift?

Posted from TSR Mobile
2. when you get a particle in SHM you use the cos or sin equations but thats only if there motion starts at the amplitude or the center. this one started in between them 2 though, so would the equation be x=Asin(wt + p) where p is a phase shift translation that moves the graph of its motion back to the normal sin curve so you can do all your usual calculations with the sin graph.

3. Like that but the red one wouldnt be that far translated, it would be the brown one moved to the right slightly. so youl need a translation constant to get it back to the sin curve
4. i just realised you could start the motion model when it is at the bottom so there is no need for a phase shift wow im so sad. so glad that m2 was a good exam
5. Just worth noting that the January 2008 paper was roughly 88% raw for 100 UMS. I reckon this was a much harder paper.
6. (Original post by bred123)
when you get a particle in SHM you use the cos or sin equations but thats only if there motion starts at the amplitude or the center. this one started in between them 2 though, so would the equation be x=Asin(wt + p) where p is a phase shift translation that moves the graph of its motion back to the normal sin curve so you can do all your usual calculations with the sin graph.
Oh I see what you mean, usually refer to it as some offset epsilon, so it threw me off

Posted from TSR Mobile
7. (Original post by JoeyTr)
I know this probably sounds weird but how did everyone's classmates find it? I was the only person doing it at my school so didn't really get the perspective. I don't really think people on the StudentRoom is a fair sample of how difficult people found the paper generally haha!
Personally, I found it harder than all papers between 2005 and 2015. I still managed to solve it, but two SILLLLLLLYYYYY mistakes made me lose around 5~6 marks I guess....
My peers found it hard too, and some did not even finish the paper....
8. Can someone recall question 7 part (iii) please. I think I got a=-10x rather than a=-10gx !!! :'(

Also question 5 (part 1) would be helpful
9. Just found out I lost around 10 marks max... giving me 62/72....
Btw, did you guys know that for 7(iv), Amplitude is larger than distance between Equilibrium position and point of natural length, so need to use suvat again....
10. (Original post by Mandos)
Can someone recall question 7 part (iii) please. I think I got a=-10x rather than a=-10gx !!! :'(

Also question 5 (part 1) would be helpful
I got -40.....
5.i, it was mg(2-3cos()) and height was 5/3 a
11. (Original post by cam5morrison)
Just worth noting that the January 2008 paper was roughly 88% raw for 100 UMS. I reckon this was a much harder paper.
I agree. In fact, I thought it was harder than any paper between 2005 and 2015
12. I made the same mistake as you, and got a=-40gx, but I realise now that when you equate tension-weight=ma (or something like that) your m in ma, is actually 4m, since it's a given quantity from the particles coalescing to have mass 4m. I just wrote ma and didn't think about it...

(Original post by JxK^2)
I got -40.....
5.i, it was mg(2-3cos()) and height was 5/3 a
13. (Original post by JxK^2)
I got -40.....
5.i, it was mg(2-3cos()) and height was 5/3 a
I got -40g lol
14. Anyone here doing M4 as well?

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 27, 2016
Today on TSR

Am I pregnant?

...or just paranoid?

Have I ruined my eyebrows

Discussions on TSR

• Latest
• See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Useful resources
Discussions on TSR

• Latest
• See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.