Applied Maths Aftermath

Jonathan

Well what did you think?

I don't think I've seen an easier question 10.. ever.

lemur option

totally, possibly the easiest paper in the last 5 years. Couldn't have gone any better. If anyone has a list of aswers please post. I think I was alright for most, just 10 (b) that i may have made a slip on.

JC 2K3

Sarcasm?

That was hard. I only got 3 and 5 fully right. I messed up a sign in 4, but I reckon I won't lose too many marks over it..

1(a) was píss, but 1(b) was horrible. I had a massive equation for b. Apparently, you had to keep fighting with the equation and you got b=1 eventually.

I messed up 2, got 19 mins for the part(a)(pretty sure that's wrong) and I'm not too confident about part (b) either(it wasn't actually too bad, I just kinda panicked in the heat of the moment).

10.... I thought I could count on it and it let me down. Part (a) was grand as usual, but part (b).... very messy. Didn't get the second part out, didn't realise that you could just let a = 0 when v = max.

Markswise I probably didn't do all that badly, but I'm rather disappointed.

Grudaire

I loved that paper!

But what was number seven B about?

cookiemonst3r

i couldnt get the connected particles question out. i kept T=0... pretty sure thats wrong. And in the impacts nd collisions question i kept gettin 0 for the speed

mathew

Was happy enough I suppose

Same as JC with 1(b), gave up on the equation instead of working it to the very end.
Question 2 was lovely,
3 was a bit tricky, but I got most of it out
4 same as 3
6 was a bítch, spent 10 mins and gave up, left me only 15 mins to the whole of question 5, having not studied it at all, got all of it out except b(ii). got alpha instead of 90-alpha.
Question 10 was amazing. Couldnt have been easier!

JC 2K3

Just to clarify, are people being sarcastic re:Q10 or am I an idiot?

DtotheK

Question 10 was tricky , even part a i thought. i wont get the last 5 marks for a , and part b was all over the shop, i had an equation with v^4 and v^2, but hadnt time to solve.
Question 4 was also weird... i was unsure what acceleration the pulley has but got answers.. of sorts
The rest was fine. collisions was great and i barely studied it!! projectiles was grand but i messed up at the very end and got tanalpha = 3!!!! so annoying



Fúck yessss it's allll overrrrrr!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

JC 2K3

I LOVED 3.

It was such a nice question, I did it in 10 minutes and it put me at ease after Q1 and 2 being not so good.

What were people's answers to Q2 btw?

DtotheK

JC 2K3 wrote:

Just to clarify, are people being sarcastic re:Q10 or am I an idiot?

I hope sarcastic. but in a poll months ago it was peoples favourite question on the paper.. which worries me

cookiemonst3r

DtotheK wrote:

The rest was fine. collisions was great and i barely studied it!! projectiles was grand but i messed up at the very end and got tanalpha = 3!!!! so annoying

I got that too! Maybe there was a misprint in the exam...

ZorbaTehZ

Very, very happy with the paper. That said, the statics question looked nasty, as did the SHM&Circ. so I was glad that I could keep away from them
My answers please correct them if you think one is wrong.
I did only 6 questions, Q1-5 and Q10.

Q1(a)(i) 5.4
(ii) 100
(b)(i) b=1

Q2(a)(i)24i+32j
(ii)24minutes
(b) d=48.04m

Q3(a) 15degrees and 75degrees
(b)

Q4(a) 2.149s
(b)(i)
(ii) T = 48mg/(5m+48)
(iii)Show that its acceleration is zero.

Q5(a)(i) 6-3e, 6+2e
(ii)
(b)(i) A:uSina, B:0.5uCosa
(ii) [pretty sure this is wrong] (90-a) . . . . . .EDIT: This is actually right.
(iii) [pretty sure this is wrong] 2u^2 - {2u^2Sin^2a+u^2Cos^2a} . . . . . .EDIT: Uhmmm, nope this is still wrong.

Q10(a) y=1/(Cosx + 1)
(b)(i) 44.123m/s
(ii)56.569m/s

Anyone else think that this whole day has just been one huge anti-climax?

ZorbaTehZ

cookiemonst3r wrote:

I got that too! Maybe there was a misprint in the exam...

0=Theta
Did you let Sin(0-45) at the beginning? Because if you did then you end up with Tan(0-45)=3 and then you can use A+B formula to change it.

JC 2K3

90-A is right for 5(b)(ii) (I actually just wrote 90, forgot it was the angle of deflection), however, 5(b)(iii) was u^2(cosA)^2

Nehpets

Wow I actually got some right, prob still failed it.

Biology went well so I won't be using it haha

cocoa

i thought it was ok, I'm gonna go ahead and start making an answer list here, if I'm feeling really obsessive i might make solutions later:

1(a)(i)5.4m/s
1(a)(ii)100m

1(b)(ii)b=1

2(a)(i)24i+32j
2(a)(ii)17minutes

2(b)48.04m

3(a)15deg or 75deg

4(a)t=2.1sec

4(b)(ii)T=48mg/(5m+48)

5(a)(i)VQ=2e+6 VP=6-3e

5(b)(i)A=usinA B=ucosA/2
5(b)(ii)90-A
5(b)(iii)u^2cos^2A

9(a)28.13cm

9(b)(i)1.075
9(b)(ii)0.032kg

10(a)y=1/(cosx+1)

10(b)(i)sorry, i got a wrong answer and haven't had time to work it out again.
10(b)(ii)root(3200)

edit: sniped... sigh... working out arguments for answers that don't agree now...

lemur option

answer to 1)b
split the diagram into three parts

A- accelleration, 0-t1 (time), area = pd
B- constant velocity, t1-t2, area = d(1-p-q) the whole area minus the other two
C- decelleration, t2-t3, area = qd

average speed = d (total distance)/t3(total time)

S=((u+v)/2)t
pd= v/2 ( t1) => 2pd = v(t1)

d(1-p-q)= v(t2-t1)

qd= v/2(t3-t2) => 2qd=v(t3-t2)

adding
2qd +2pd+d-pd-qd= vt3
d(p+q+1)=vt3
d/t3= v/(p+q+1)
b=1

probably an easier way of doing it. but it was by no means impossible

ZorbaTehZ

lemur option wrote:

probably an easier way of doing it. but it was by no means impossible

Did the exact same thing mate, however in the process I pretty much destroyed my speed/time graph with all the letters strewn all over it

DtotheK

cookiemonst3r wrote:

I got that too! Maybe there was a misprint in the exam...

hope so but i doubt it! we'll prob get most marks, prob just a stupid slip somewhere

DtotheK

JC 2K3 wrote:

90-A is right for 5(b)(ii) (I actually just wrote 90, forgot it was the angle of deflection), however, 5(b)(iii) was u^2(cosA)^2

YESSSS!!!

and i think his thing is the same as u^2(cosA)^2.. or else it's close ish. i just simplified it in the case minute when i notices the sin^2 and cos^ =1 stuff

PeterMC

ZorbaTehZ wrote:

Very, very happy with the paper. That said, the statics question looked nasty, as did the SHM&Circ. so I was glad that I could keep away from them
My answers please correct them if you think one is wrong.
I did only 6 questions, Q1-5 and Q10.

Q1(a)(i) 5.4
(ii) 100
(b)(i) b=1

Q2(a)(i)24i+32j
(ii)24minutes
(b) d=48.04m

Q3(a) 15degrees and 75degrees
(b)

Q4(a) 2.149s
(b)(i)
(ii) T = 48mg/(5m+48)
(iii)Show that its acceleration is zero.

Q5(a)(i) 6-3e, 6+2e
(ii)
(b)(i) A:uSina, B:0.5uCosa
(ii) [pretty sure this is wrong] (90-a)
(iii) [pretty sure this is wrong] 2u^2 - {2u^2Sin^2a+u^2Cos^2a}

Q10(a) y=1/(Cosx + 1)
(b)(i) 44.123m/s
(ii)56.569m/s

Anyone else think that this whole day has just been one huge anti-climax?

Ya got most of them too, didn't do Q2, and for 5B, ii) I also said something about 90 and a. iii) Cant remember, as for Q6 A, was this about differentiating for the first bit? B, thought was fine!

This was my second time doing AP Maths and I thought it was much easier than last year and definitely the easiest paper in years, me thinks the marking is going to be strict!

ZorbaTehZ

It was pretty obvious that Q7 was going to be difficult after the joke of a question there was last year, but I thought there'd be a nice Q6 since last years wasn't the nicest.
I read "...impinges upon and coalesces with another bead ..." and said no fucking way, lol.

lemur option

are you guys sure about 90 -A for question 5b? I got that the i component was 0 so the ball would go along the j axis giving it a deflection of 90 + A

JC 2K3

DtotheK wrote:

I hope sarcastic. but in a poll months ago it was peoples favourite question on the paper.. which worries me

It WAS my favourite question.

Seriously, IIRC my equation at the end of part (b)(i) was:

v = root(3200 - 3200e^-15/16)

....

Jonathan

ZorbaTehZ wrote:

Anyone else think that this whole day has just been one huge anti-climax?

Yip. Feels wierd. I think its cause most people had their night out on wednesday and the fact that we couldnt go made it worse..

cookiemonst3r

does coalesce mean they stick together??

ZorbaTehZ

cookiemonst3r wrote:

does coalesce mean they stick together??

Yup.

PeterMC

cookiemonst3r wrote:

does coalesce mean they stick together??

yeah, so u treat them as the one mass

ZorbaTehZ

JC 2K3 wrote:

10.... I thought I could count on it and it let me down. Part (a) was grand as usual, but part (b).... very messy. Didn't get the second part out, didn't realise that you could just let a = 0 when v = max.

The other way to do it, and the way I did it, is to take your equation from part (i), and let s tend to infinity.

lemur option

anyone care to show an answer for 10 (b) a worked out answer I believe I got quite close to JC 2K3's answer works down to 4.41 something.

JC 2K3

ZorbaTehZ wrote:

The other way to do it, and the way I did it, is to take your equation from part (i), and let s tend to infinity.

FÚCK!!

And there was me trying to let dv/ds = 0 and it not being possible.

Sigh....