M4 - Edexcel 2008 and 2009 mark schemes needed please!

Don't tell me I need to google it because I have already and found nothing, I've also tried websites like freeexampapers.com but no luck. Please can someone help me out!

Thanks in advance! :smile:

Reply 1

2710

Oh I didn't see this thread, but I need them too. Anyone help?

Reply 2

2710

Hmm, if no one has it, I have a better idea. Do you want to compare answers with me?

So far I have got (June 09):

1)

\dfrac{mu^2}{6}

\dfrac{1}{2k} ln |\dfrac{8}{5}|

3) a)

233^o

0.28 km

1.98 km

I'm not sure about q3) I think I might have got them wrong.

4) a) Show that question

b) I got cos theta = 0.8 and -0.625, but -0.625 gives a ridiculous angle so it is ruled out

c) I got it to be stable,

\dfrac {d^2V}{d\theta ^2} = 34.2

Thats all I have done so far, Ill post the rest when Im done

Reply 3

buckett

Sure thing:

1) It was a fraction so I got 1/3 (1/6mu^2)/(1/2mu^2

2) The same

3) a) the same
b) 1.98km could be wrong
c)gave up thought i was wrong

4 Didn't bother with, I'm confident on that topic...

5)a) show that
b) Impulse -2i -2j which is parallel to i+j
c) e = 0.2

6) x=f/n^2(1-cos(nt))

Reply 4

2710

for 5c)

I used the formula:

v1- v2 = - e(u1 - u2)

and I get:

e = \dfrac{j}{i+4j}

which seems similar to your answer of 0.2, if I take the speed instead of the vector form. i.e 1/5

My question is, can you just work out restitution like this? Shouldn't the collision be linear for you to use Newtons law of restitution? Or can you just stick everything into the formula....

Also, yeah, for the 1st question, I got a 1/3 too, forgot the fraction part.

And q 3 is just a nightmare, do you mind showing your working, or Ill show mine

Reply 5

buckett

For the NLR question you consider the components along the line of centres, because that's the direction the "bouncyness" happens if that makes sense. So what I did to find the components acting along i+j was i found the scalar product of each vector with i + j so the NLR formula gives:

v1.(i+j) - v2.(i+j) = e(u2.(i+j) - u1.(i+j))

then whack then values for v1...u2 into that and 1/5 drops out.