Edexcel AS/A2 Mathematics M1 - 8th June 2016 - Official Thread

Hi
Can someone help me with why the impulse for part B is 2100 and not 2700 ?

Can you post working to show how you got 2700?

I have no clue how to find parallel vectors. Could someone help me out with the b) part ?


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I have no clue how to find parallel vectors. Could someone help me out with the b) part ?


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can you tell me what paper it is?

Here:

Thank you very much. It was very helpful


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Hi
Can anyone help me with this vectors question
The whole question is quite confusing

Is this from an official paper?

Hi
Can anyone help me with this vectors question
The whole question is quite confusing

a) 6i + 8j
If he is on the pipe he must have an i value of 6. If he the radio tower is SW of him, the j value between him and the mast is the same as the i value between him and the mast. The tower is at (0i + 2j) and he is at (6i + xj) --> the i difference is 6 so the j difference is 6 as well, meaning he has a j value of 8

b) His distance from the origin is route(6^2 + 8^2) (pythag) which is 10km. If they're travelling at 5km/h, it'll take 2 hours.

c) 6i - 4j
Same logic as a)

Didn't try d) because idk if I've got this right

Edit: fixed typo

For all North West and South West etc is it the difference of i components and j components , or is there a negative sign needed?

Kind of both, it depends which direction you're going. If you think about it on a graph, North is positive (+j), West is positive (+i), South is negative (-j), and East is negative (-i).

So say O is (0,0) and P is (x, 5), and P is directly NW of O. The j difference is 5 so the i difference is 5 as well and because W is positive, its 5i.

If P were NE of O, the i difference is still 5 but because E is negative, its -5i.

So taking N is J and E is I
NE : +J +i
SE: -J + i
SW: -J -i
NW: +J-i

So why for part a were it was SW we took both i and j as +ve

Because if the mast was SW of the man, he was NW of the mast.
Alternatively you could have done man(6i + xj), mast(0i + 2j).
The difference is -6 on both i and j because the mast is SW, so
(i) 6-6=0 and (j) x-6=2

I find it helps to draw it on a graph

OMG I'M LOSING MY MIND I'VE FORGOTTEN BASIC MATHS I UNDERSTOOD THIS LIKE A MONTH AGO NOW WHEN I DO M1 AFTER AGES I'VE FORGOTTEN. I'm going to seem really stupid :/ but can anyone explain why it's F = 2Tcos45 Why am I stuck on the easy things

The hypotenuse is F, and so shouldn't it be Fcos45 = T x2 so F = 2T/cos45?

The hypotenuse of T isn't F, the hypotenuse of the resultant off boths T's is F.

Resolve each tension force separately, then add both forces together. Seen as the tensions are equal, you can just times by 2, as they resolve the same horizontally and vertically.