EXAM2 THOUGHTS +ANSWERS

[joechan521]

It looks like the end of exams for many people.
exam2's difficulty is alright, very normal.
here are some of my answers, please correct me if im wrong

BEDBEBACDC
DAECADCEBC
AB

Q1a) 2cis5pi/6
d) -z1 and -z1bar
Q2a) arctanx + x/(1+x^2),  gradient=0
c)ii  0.285
e) pi/4 - .5ln2
f) 0.15

Q3a) g/2
b)3g/2
c)g/8
d)19.5 or 19.8 i couldnt read my writing
e) A=7.8 B=30.4

Q4b)1118
c)4.6
d)56
e)3010  
d and e im not sure

Q5 a)14.1
c)x= fint(20-2arctanT )dt from 0 to t
d) 60.7
e) integral from 8 to Tc (20-2arctan(t))dt + 60.7-(Tc-8)26.178=0
f)Tc=15s

[enwiabe]

I can confirm that D and E of question 4 are correct.

[Ahmad]

The short answers all look like mine. Well most of them. /sick my head

[Sheikh05]

I got the first 3 questions. Started to make some mistakes in the last 2 =(. Still better than I thought I'd get. I'm pretty happy  

[cara.mel]

Agree with all the short answer

A few of the MC I found really hard and guessed them =/

[Daniel15]

A few of the MC I found really hard and guessed them =/

Heh, I started with the extended response questions, and spent quite a long time on then. I ended up having to guess a whole heap of multiple choice questions (like 5 or so) because I was running out of time.

[cara.mel]

Actually I remember the angle I got on the plane thing I have a number bigger then that I think. Wasn't really sure what I was doing there, I tried to make a triangle using the velocity vector and combined the i and j together, so I had k, my i/j mix, and then tried to triangle it xD Yay for method? (think it was arctan 4/50)

On all my exams, I manage to spend, plus or minus 2 minutes, the 'recommended' time for each question. Eg today multi choice just over half an hour, short answer finished with 4 or so mins to go. I do that without trying =/

[Matt89]

Actually I remember the angle I got on the plane thing I have a number bigger then that I think. Wasn't really sure what I was doing there, I tried to make a triangle using the velocity vector and combined the i and j together, so I had k, my i/j mix, and then tried to triangle it xD Yay for method? (think it was arctan 4/50)

I did something weird and ended up with 76 degrees

[Ahmad]

The velocity was something like 30i + 40j - 4k. If you imagine the angle that makes with the horizontal.. that's like 50 on one side and 4 on the other. So it'll be very small. I agree with the 4.6 or whatever.

[cara.mel]

The velocity was something like 30i + 40j - 4k. If you imagine the angle that makes with the horizontal.. that's like 50 on one side and 4 on the other. So it'll be very small. I agree with the 4.6 or whatever.

Yay, what I did ^_^
btw I hope you get better Ahmad
I was sick during spec 1/english, but my body tends to forget it's sick during the actual exams =)

[hakeemthedream]

i didnt get that

accidently used stupid position vector

aaggh

and got one other small thing wrong in the mechanics question - very stupid

and a mark somewhere else

max 5

pllus 5 off in first one (awful mistakes)

45 raw? is it possible?

[Matt89]

The velocity was something like 30i + 40j - 4k. If you imagine the angle that makes with the horizontal.. that's like 50 on one side and 4 on the other. So it'll be very small. I agree with the 4.6 or whatever.

Sorry but where does the 50 come from?

[Ahmad]

rt[30^2 + 40^2]

In reality though, I didn't do it this way. I used a vector method. I only mentally thought of this way as a check for reasonableness.

[Matt89]

rt[30^2 + 40^2]

In reality though, I didn't do it this way. I used a vector method. I only mentally thought of this way as a check for reasonableness.

Oh i just figured it out! dammit! For some reason i totally ignored the i and j component and thought "angle with the runway.... the k component determines altitude, so only that bit matters". stupid, stupid, stupid..... Oh well, only 2 marks, my total marks lost is probably about 15. Hopefully i still get a 35+ RAW

[bilgia]

i made a mess of that question....