OCR MEI M2 - 18th May 2016

Apparently it was an easier paper, do you think there is a chance its gonna be really high like 64 from June 11? Unlikely right ? I am really hoping its around the same as last year :/

Original post by MintyMilk

Wouldn't be surprised if we had the exact same grade boundaries as last year: 62, 56, 51 for A*, A, B

Reply 61

chemari1

2

the coefficient of friction was 1.57 right? Work done by tension+ initial kinetic energy = final ke + gain in gpe + work done against friction yessss???

Reply 62

MintyMilk

3

Original post by chemari1

the coefficient of friction was 1.57 right? Work done by tension+ initial kinetic energy = final ke + gain in gpe + work done against friction yessss???

I think that was the right method, but I got roughly half your value, being 0.78, while everyone else seems to have got 0.866.

Reply 63

chemari1

2

Original post by MintyMilk

I think that was the right method, but I got roughly half your value, being 0.78, while everyone else seems to have got 0.866.

did you get one of the rods in tension of 393 or 394?

Reply 64

Connorbwfc

5

For the question which said that the object of mass 0.05kg is shot of with a speed of 10ms^-1 relative to P. Does it mean this is relative to the speed of P before it was shot or or after it was shot off and how were we meant to know this? This is what I am having problems understanding.

Reply 65

MintyMilk

3

Original post by Connorbwfc

For the question which said that the object of mass 0.05kg is shot of with a speed of 10ms^-1 relative to P. Does it mean this is relative to the speed of P before it was shot or or after it was shot off and how were we meant to know this? This is what I am having problems understanding.

Original post by chemari1

did you get one of the rods in tension of 393 or 394?

Check the earlier pages in the thread, it's all there.

Reply 66

Charonder

7

Original post by -Gifted-

Definitely was thinking this, but for 2 marks- i just did 91.5 times by 7. :/

I did that too and I think its right because it was only the power of the tension wasnt it? Not the total power developed or anything

Reply 67

Connorbwfc

5

Original post by MintyMilk

Check the earlier pages in the thread, it's all there.

Yeah I understand, that the people on this forum are saying that it means they have a speed of separation of 10ms^-1.

However, how did we know this?

How did we know that it wasn't shot out at 10ms^-1 relative to the speed of P before it was shot? How do we know it was shot out at 10ms^-1 relative to the speed of P after it was shot?

Reply 68

chemari1

2

Original post by MintyMilk

Check the earlier pages in the thread, it's all there.

soz but it ain't, anyway, I missed out the whole of question 4, hopefully the coef of friction was 1.57 and the force on the rod (I first wrote 393 in my working out and underlined it but then I put 394 in a sentence) 393 or 394? so that I get all the marks up to that man, did c1 as well frst like so I was a bit drained

Reply 69

username1258398

19

Original post by Connorbwfc

Yeah I understand, that the people on this forum are saying that it means they have a speed of separation of 10ms^-1.

However, how did we know this?

How did we know that it wasn't shot out at 10ms^-1 relative to the speed of P before it was shot? How do we know it was shot out at 10ms^-1 relative to the speed of P after it was shot?

Consider this: the small object (call it R) is shot out at 10 ms^-1 relative to P's initial speed, i.e. at 8ms^-1 relative to the ground, with P moving off at 2ms^-1. Why is P's speed going to change? R has already left, it can't influence P's motion any more.

It has to mean 10ms^-1 relative to P's speed after the shot.

Reply 70

-Gifted-

6

The fact that the poll is biased towards greater than 60, i am so screwed for this exam. Defo won't be getting a 90 by dropping 6 marks :/

Reply 71

chemari1

2

does anyone remember the numbers for thecoefficient of frition question?
was it
0.5 x 6 x 49 + 91.5 x 8 = 6x9.8x8sin30 + 0.5 x 6x1 + 8 F
ke work done by tensionsion gain in gpe final ke work done against friction

F=80.1, and coefficient= 80.1/ 6x9.8xcos30 = 1.57!!!!!!
I musta been right kiddars

(edited 7 years ago)

Reply 72

-Gifted-

6

Original post by chemari1

does anyone remember the numbers for thecoefficient of frition question?

friction was 44.1 N, and the weight was 6g where the block was inclined at 30 degrees.

Reply 73

username1258398

19

Original post by -Gifted-

The fact that the poll is biased towards greater than 60, i am so screwed for this exam. Defo won't be getting a 90 by dropping 6 marks :/

I really doubt it'll above 60.

Reply 74

-Gifted-

6

Original post by StrangeBanana

I really doubt it'll above 60.

Legit man, if it is, I am done. Give up.

Reply 75

MintyMilk

3

Original post by -Gifted-

Legit man, if it is, I am done. Give up.

You're gifted, we get it already, 66 will almost 100% be an A*. It's only not been an A* once ever, and this was a harder than average paper.

Reply 76

Connorbwfc

5

Original post by StrangeBanana

Consider this: the small object (call it R) is shot out at 10 ms^-1 relative to P's initial speed, i.e. at 8ms^-1 relative to the ground, with P moving off at 2ms^-1. Why is P's speed going to change? R has already left, it can't influence P's motion any more.
It has to mean 10ms^-1 relative to P's speed after the shot.

How many marks do you think I'll get for this question if I treated it as 10ms^-1 relative to the initial speed.
So: 2*(0.5)=0.05*-8 + 0.45V and solved for V?

Also do you think the picture I've attached is an okay method for showing that the plane isn't smooth?