Q9 and Q10 (1 Viewer)

[Wahlito]

ok for (b) WTF! Did anyone get this question...

and the fish thing in part (c) What The!?

Q10 (a) was alright but Q10 (b)... OMG

 

[bails]

I skimmed through them, went who could be bothered and left.

 

[Nezz]

i think i did ok in 9b... i could be making it up though so dont rely i what i got...

9bi: 30 degrees

9bii: BAC = 1/2 r^2 angle BAC (angle BAC = 2 angle BAO)
= 1/2 r^2 pi/3

9biii: BOC = 1/2 r^2 angle BOC (angle BOC = 120)
= 1/2 r^2 2pi/3

9biv: Area = Area BOC (circle 1) - Area OBC (circle 2)

Where area OBC (circle 2) = Sector ABC (circle 2) - (area triangle AOB + area triangle AOC)
= Answer from part ii - 2 x area triangle BOA
(using area triangle = 1/2 absinC)

forget what i ended up with but thats what i did from what i can remember... not sure if its right... what did everyone else do?

 

[Takuya]

Yes my values for BAC and BOAC were something like that...

I didn't get the area of triangle out because I was too pressed for time.

 

[Russian]

what were the answers for 10a iii and iv

 

[t-i-m-m-y]

10 b was easy lol not really the very last last part was hard- i'll prolly get 1 outta 2....but seriously.. look @ 2002 HSC and u'll kill urself if u didn't do it.. its practically the same question- have a close look at q10 of last years one

 

[iambored]

Originally posted by t-i-m-m-y
10 b was easy lol not really the very last last part was hard- i'll prolly get 1 outta 2....but seriously.. look @ 2002 HSC and u'll kill urself if u didn't do it.. its practically the same question- have a close look at q10 of last years one

i did do it, and recognised it when i got to this one, but didn't get enough time to think clearly without panicking that the time was running out, and then there was a pulley? ugh

 

[Sah]

umm the answer for the fish was v=3u/2 i think

for 10(b) last one the answer i got was x=r and it seemed ok (not 100% sure)

 

[SmokedSalmon]

Q9 b) I did but probably no where close to correct... oh well I incorporated my formulas!

c) i)
Considering V = L/t
(speed = distance/time)
And V = v-u
then
t= L/(v-u)

So E = aLv*3/v-u

(ii) Take the deriative of (i), make DE/Dv = 0
And find v = (some answer involving u)

 

[eeyore]

Yeah that stupid fish question definately killed me
i had no idea what the hell to do with it!