The Edexcel M2 (31/05/12 - AM) Revision Thread

Will you still get full marks if you use an alternative method but get the right answer?

Oh god, dreading this now. I just hate the collisions and moments questions.

Also the energy questions throw me sometimes, I just end up doing the wrong calculation. :/

Pretty confident on the whole differentiation thing and impulses though.

Reply 82

Patchey1000

2

Original post by snow leopard

Post #49

Thank you dude!

Reply 83

oli_G

12

Original post by Amr314

can someone give advice on this question?

a particle is projected from a point on level ground with a speed (u) ms-1 and at an angle (alpha).

Maximum height: 42m
range: 196m

Find u and alpha..

The two variables are really throwing me off

Ok, you know that

42 = \frac{u^2sin^2\alpha}{19.6}

So,

u^2sin^2\alpha = 823.2

t = \frac{\sqrt 837.2}{9.8}

Also you know

192 = ucos\alpha \times 2t

So,

ucos\alpha = \frac{940.8}{\sqrt 837.2}

And,

u^2cos^2\alpha = 1057.22.........

So,

u = \sqrt 1880 = 43.4 m/s (3sf)

Sub back in to find alpha.

That's my best shot anyway, is a difficult one.

(edited 11 years ago)

Reply 84

Benjyxo

Original post by HadrianH

Thanks a lot. I just need a little more practice.

Can you explain the angle from vertical/horizontal? :smile:

Yeah, just do a few exercises! The lucky thing about M2 is every question is the same principle, so if you do enough you'll get them every time :smile:

For the angle, I like to draw a picture firstly, helps me visualise.
The weight will go through the CofM which you figured out from a) then it's just trigonometry really.
I like to draw another diagram with just the main triangle (the weight going through the CofM and the y and x as the other sides to the triangle)
Just be sure to get your alpha/theta in the right place, and for some questions you may have to do the length of one side (L) - y to get the correct triangle..

I hope this is fairly clear :smile:

Reply 85

Braniac101

is this the basic method everyone uses for work energy principle:

total initial energy - work done against restive force + work done by engine/cyclist = final energy
and then sub everything in and just rearrange and find out what you need
or is there a better way
if som can you do a question with a turoial of how you go about
thanks

also, what the best way to practice on the night before,

Reply 86

aurao2003

3

Hi
Can someone kindly post a link for any relevant past papers? I am having difficulty accessing the Solomon papers. As many as possible would be appreciated. Mechanics has to become my middle name!

Cheers

Reply 87

jqian

1

Original post by aurao2003

Hi
Can someone kindly post a link for any relevant past papers? I am having difficulty accessing the Solomon papers. As many as possible would be appreciated. Mechanics has to become my middle name!

Cheers

http://www.mathspapers.co.uk/edexcel.html scroll down, all the past papers up to Jan 12.

Reply 88

HadrianH

Original post by Benjyxo

Yeah, just do a few exercises! The lucky thing about M2 is every question is the same principle, so if you do enough you'll get them every time :smile:

For the angle, I like to draw a picture firstly, helps me visualise.
The weight will go through the CofM which you figured out from a) then it's just trigonometry really.
I like to draw another diagram with just the main triangle (the weight going through the CofM and the y and x as the other sides to the triangle)
Just be sure to get your alpha/theta in the right place, and for some questions you may have to do the length of one side (L) - y to get the correct triangle..

I hope this is fairly clear :smile:

Thanks a lot, I appreciate your help.

Do you have any fairly challenging CoM questions that you can share? :biggrin:

Cheers!

Reply 89

Hamburglar

Question 8 on January 2010 paper, what the ****.

I have the mark scheme, and I still have no idea what's going on. I get part a now in hindsight.

But parts b and c make no sense.

Anyone care to explain?

Reply 90

Mathematix

2

m2 y u make me do 1 silly mistake every paper? :mad:

Reply 91

Kaiser7

6

Original post by Kaiser7

Can someone please explain Thrust to me? When does it happen, and in which direction does it act?

Any help please?

Reply 92

GnomeyD

has anyone on here done the past paper from june 2007? for the first question it gives the answer as 32N, and this just doesn't seem to make any sense.

Reply 93

jqian

1

Original post by GnomeyD

has anyone on here done the past paper from june 2007? for the first question it gives the answer as 32N, and this just doesn't seem to make any sense.

It does make sense, I've done it. You have to work out the driving force first, by dividing their power by the speed of the car(or whatever it was). Then you have resolve along the plane and all forces going up the plane should equal to all forces going down the plane.

Reply 94

BobLoblawLawBlog

OP

16

Original post by dsinghdahiya257

Will you still get full marks if you use an alternative method but get the right answer?

If it says, for example: by considering energy, calculate the velocity of P as it hits the ground, and you used a projectile method, you wouldn't get the marks, i'm not actually sure if you would get any. But if it didn't specify a method, you could do it an alternative way and get full marks as long as it actually works.

Reply 95

dsinghdahiya257

10

Original post by brittanna

If it says, for example: by considering energy, calculate the velocity of P as it hits the ground, and you used a projectile method, you wouldn't get the marks, i'm not actually sure if you would get any. But if it didn't specify a method, you could do it an alternative way and get full marks as long as it actually works.

Okay it has to specify...goood. :smile:

Reply 96

Mr Maths

I actually don't understand the work energy principle. What is it?!

Reply 97

Rough Silk

Original post by GnomeyD

has anyone on here done the past paper from june 2007? for the first question it gives the answer as 32N, and this just doesn't seem to make any sense.

Ahhhh! I've done this question and I'm assuming you've used sin alpha as 5 over 21? (well I guess you have because that's why I couldn't do it)

Sin alpha is actually 1 over 21 and the paper we have has a mistype on it.

Don't worry, I'm sure I spent longer raging over this than you did :L

Reply 98

GnomeyD

Original post by JohnSimmons

Ahhhh! I've done this question and I'm assuming you've used sin alpha as 5 over 21? (well I guess you have because that's why I couldn't do it)

Sin alpha is actually 1 over 21 and the paper we have has a mistype on it.

Don't worry, I'm sure I spent longer raging over this than you did :L