Post by: brenden on November 04, 2016, 11:15:22 am
(http://i.imgur.com/yFSBtYT.png)
(http://i.imgur.com/6P5NY8v.png)
(http://i.imgur.com/MHQCEn6.png)
(http://i.imgur.com/wPfLA5O.png)
(http://i.imgur.com/RSgrslb.png)
(http://i.imgur.com/wx0DboB.png)
Post by: angrypotato1 on November 04, 2016, 11:16:19 am
How'd you go? What was the trickiest question?
Suggested answers will be in this thread once complete!
Probably second last conceptually, but hardest to get full mark on the last one
Post by: Jemin99 on November 04, 2016, 11:20:16 am
What is your prediction of A+ cutoff?
Post by: Maths Forever on November 04, 2016, 11:23:26 am
How'd you go? What was the trickiest question?
Suggested answers will be in this thread once complete!
Would you have a copy of the paper by any chance? :)
Post by: brenden on November 04, 2016, 11:25:32 am
Would you have a copy of the paper by any chance? :)Not yet :)
Post by: jazzycab on November 04, 2016, 12:09:28 pm
Here are my answers only:
1a) Force Diagram with 20g gravitational force, and Tension shown UP the rope (P already shown on diagram)
1b) Use right-angled Trig to get
1c)
2)
3)
4)
5a)
5b)
6)
7)
8a)
8b)
8c)
9)
10)
Post by: Jemin99 on November 04, 2016, 12:17:28 pm
Done this quite rushed, so possibly some errors.Question6 its 4+4root3i
Here are my answers only:
1a) Force Diagram with 20g gravitational force, and Tension shown UP the rope (P already shown on diagram)
1b) Use right-angled Trig to get
1c)
2)
3)
4)
5a)
5b)
6)
7)
8a)
8b)
8c)
9)
10)
Post by: shlblk on November 04, 2016, 12:25:15 pm
Question6 its 4+4root3i
I had 4 + 4root3i as well.
Can confirm all other answers were the same except for the confidence interval (which I stuffed up).
I had 25g as 245N, that shouldn't lose any marks though right?
With the confidence interval when I divided 2625 by 25 I made an error and got 15 instead of 105. Then I used this to confidence interval but ignored the integer bit and used the exact values. Do you think I'll scrape a mark for that?
Also do you think the A+ cut-off will be 37 again?
Post by: Dumi on November 04, 2016, 12:28:04 pm
Post by: brenden on November 04, 2016, 12:29:05 pm
Done this quite rushed, so possibly some errors.Do you have a copy of the exam?
Here are my answers only:
Post by: StupidProdigy on November 04, 2016, 12:30:14 pm
I had 4 + 4root3i as well.Unforunately they are quite likely to penalise the 245N. It has come up in a few examiners reports about students using g=10 when they shouldn't, but lets hope the examiner doesn't care for your sake!
Can confirm all other answers were the same except for the confidence interval (which I stuffed up).
I had 25g as 245N, that shouldn't lose any marks though right?
edit: thought you had 24.5 and used g=10, ignore what I said
Post by: shlblk on November 04, 2016, 12:31:13 pm
Unforunately they are quite likely to penalise the 245N. It has come up in a few examiners reports about students using g=10 when they shouldn't, but lets hope the examiner doesn't care for your sake!
I did use g as 9.8...25*9.8 = 245? Or should I have left it as 25g?
I didn't use g = 10 though.
Post by: angrypotato1 on November 04, 2016, 12:33:18 pm
I did use g as 9.8...25*9.8 = 245?
yeah lol it's definitely fine. I think it's preferred as they state at the start g=9.8, it's possible you get penalised for NOT subbing in 9.8 as g
Post by: shlblk on November 04, 2016, 12:36:14 pm
Post by: BNard on November 04, 2016, 12:38:46 pm
Post by: jammin on November 04, 2016, 12:48:28 pm
I think this year's was really quite easy, they'll probably make next exam quite tough though
Quite happy, don't think I dropped a mark yet
Post by: Sarinamfgh on November 04, 2016, 12:51:09 pm
What was question 4 about?
Post by: supernamekian on November 04, 2016, 01:20:28 pm
Hey Guys,
What was question 4 about?
Wasn't that the one with the crystal and you needed to find the rate of change when t=1?
Post by: Callum@1373 on November 04, 2016, 01:36:39 pm
Post by: Orb on November 04, 2016, 01:40:01 pm
With rank 1 SAC's and a definite 40/40 on exam 1, can I afford to drop any marks on exam 2 for premiers and/or 50 raw?
Premiers you need 120/120, for a 50 119/120
Post by: supernamekian on November 04, 2016, 01:48:36 pm
Please and thank you
Post by: ciaran3105 on November 04, 2016, 02:07:50 pm
Thanks!
Post by: supernamekian on November 04, 2016, 02:23:51 pm
Could someone please explain how to do the arc length question?
Thanks!
Well the Arc length formula was on the formula sheet, so I plugged in the given equation into the formula, hopefully that gave me the right answer
Post by: drake on November 04, 2016, 02:28:16 pm
With rank 1 SAC's and a definite 40/40 on exam 1, can I afford to drop any marks on exam 2 for premiers and/or 50 raw?
you can get a premiers award even if you lose 1 mark. it just depends on how well the state does. i lost 1 mark overall and got premiers for spesh. raw 50 depends on how hard the exam is overall. generally you can lose 1-2 marks overall and get 50, but depends on how easy or hard the exam is.
Post by: Jemin99 on November 04, 2016, 02:46:32 pm
If you were to make one arithmetic error at the very beginning of the question worth 3 marks and did everything else right would you lose just 1 or 3 marks?probs 2
Post by: Eefy on November 04, 2016, 03:34:04 pm
Post by: MightyBeh on November 04, 2016, 03:47:16 pm
Would i lose marks for leaving the weight force on the first question as mg instead of 20g? Also misread the last question and integrated rt(2-x) instead of rt(2-x^2) how many marks would i lose with the right workings?IIRC it was out of 5, probably 2; one working mark for evaluating the wrong integral, then another for the answer unless it's somehow correct anyway. :)
Post by: Jemin99 on November 04, 2016, 04:37:22 pm
Would i lose marks for leaving the weight force on the first question as mg instead of 20g? Also misread the last question and integrated rt(2-x) instead of rt(2-x^2) how many marks would i lose with the right workings?Wasnt it 25g anyways? :3
Post by: decentxion on November 04, 2016, 04:41:35 pm
Easy Exam 1 guys! Make sure you brush up on your calc skills and brace yourself for a harder Exam 2!
Post by: Jemin99 on November 04, 2016, 04:44:43 pm
I've just sent through some solutions to the admin, he might put them up! If not, I'll post them in another thread :)What do you think a cutoff for A+ be? And since it was so easy would spec omly scale up to 52 this yr?
Easy Exam 1 guys! Make sure you brush up on your calc skills and brace yourself for a harder Exam 2!
Post by: decentxion on November 04, 2016, 04:46:01 pm
What do you think a cutoff for A+ be? And since it was so easy would spec omly scale up to 52 this yr?I reckon it'll be a 36-37/40 A+ cutoff. Was as easy as the 2013 exam 1 which was my year. Nah spesh should always scale up to 55.
Post by: angrypotato1 on November 04, 2016, 04:47:39 pm
What do you think a cutoff for A+ be? And since it was so easy would spec omly scale up to 52 this yr?
I don't believe the exam difficulty effects scaling, scaling is determined by the strength of the cohort. In general, specialist students do so well in their other subjects that a perfect score in specialist is worth 5 SS points more than a normal subject
source: http://www.vtac.edu.au/results-offers/atar-explained/scaling.html
Post by: Jemin99 on November 04, 2016, 04:58:45 pm
I reckon it'll be a 36-37/40 A+ cutoff. Was as easy as the 2013 exam 1 which was my year. Nah spesh should always scale up to 55.Ur year was 38/40 for A+
Doesnt matter for you spesh god!
Post by: Jemin99 on November 04, 2016, 05:01:43 pm
I don't believe the exam difficulty effects scaling, scaling is determined by the strength of the cohort. In general, specialist students do so well in their other subjects that a perfect score in specialist is worth 5 SS points more than a normal subjectOhhhh i see, thanks man! Idk what happenning to Latin tho
source: http://www.vtac.edu.au/results-offers/atar-explained/scaling.html
Post by: brenden on November 04, 2016, 05:09:59 pm
Post by: hiendaica11145 on November 04, 2016, 05:28:16 pm
Post by: realdka on November 04, 2016, 06:18:56 pm
Post by: Jemin99 on November 04, 2016, 06:23:49 pm
Think I got around 36 or 37/40 on paper 1. What do you guys reckon I'd need on paper 2 to pull a 41 raw?Pretty sure thats about low A+ so try getting 72-3/80 on Mon
Post by: shlblk on November 04, 2016, 06:31:35 pm
I actually did better on this exam 1 as opposed to methods.
Post by: Syedali_ on November 04, 2016, 06:56:00 pm
Post by: decentxion on November 04, 2016, 07:02:33 pm
Im doing spesh , but Q1 c isnt it downwards force meant to be 20x9.8It indeed is! The downward force is equal to 20g. I assume you mean you're not doing spesh, in which case, answers with "g" are accepted as 9.8 is merely an approximation of gravity.
Post by: Syndicate on November 04, 2016, 07:12:39 pm
Im doing spesh , but Q1 c isnt it downwards force meant to be 20x9.8
I think both answers are acceptable. Using g would be more exact, though at the top it says that g = 9.8. Can anyone confirm?
Post by: decentxion on November 04, 2016, 07:13:32 pm
I think both answers are acceptable. Using g would be more exact, though at the top it says that g = 9.8. Can anyone confirm?Confirmed. Answers with g are safer, unless they ask for some sort of number answer.
Post by: Mintk on November 04, 2016, 07:16:02 pm
When I was looking for r for 1+root3, I wrote that the r would be root 2.....
Would I lose marks for the entire thing? I did everything else correct though.....
Post by: keltingmeith on November 04, 2016, 07:20:20 pm
What do I do if I did a stupid arithmetic error at the start of a question?
When I was looking for r for 1+root3, I wrote that the r would be root 2.....
Would I lose marks for the entire thing? I did everything else correct though.....
Definitely will still get some working marks - I reckon 2/3.
Post by: decentxion on November 04, 2016, 07:26:42 pm
What do I do if I did a stupid arithmetic error at the start of a question?Did you get root2 as the r for both the top and bottom? If so, it'll be hard to get more than 1 mark especially since that's the first step to the question. You'll probably get working out marks for later steps.
When I was looking for r for 1+root3, I wrote that the r would be root 2.....
Would I lose marks for the entire thing? I did everything else correct though.....
Post by: Syedali_ on November 04, 2016, 07:45:25 pm
Post by: decentxion on November 04, 2016, 08:13:29 pm
So i used g and got 156.8NThat means you got an answer of 16g for your tension T. I have an idea of why you got that answer, you probably multiplied the 20g by 4/5, instead of multiplying by 5/4. The answer you should've got was 25g, as you'll definitely need MORE than 20g (the weight of the box) in your tension of the string in order to hold it up.
Post by: Syedali_ on November 04, 2016, 08:16:44 pm
Post by: keltingmeith on November 04, 2016, 08:25:21 pm
Why 5/4 and not 4/5
The specific lines of working are:
so obviously, if you multiply by 4/5, you don't get T by itself.
Post by: Syedali_ on November 04, 2016, 08:46:09 pm
Post by: keltingmeith on November 05, 2016, 01:53:20 am
So i got 156.8 N and im pre surre its the way it should have been done , If you can explain sure
Alright - slight problem is my working is going to be identical to the sample answers. Why not show us exactly what you did? That way we can point out where there might be some issues. Whether it's because we fucked up and your working will show us how, or you made a slight mistake and we can explain why that's wrong, doesn't really matter - what's more important is that everyone here is better prepared for exam 2 on Monday.
Post by: hahahaliao on November 05, 2016, 02:01:28 am
Hi guys! I screwed up the Specialist exam 1. I lost about 11 marks . Are there any chance for me get a study score for 35 if i do a better job in exam 2? Please help me ! :( :( :(Yes there are!
Post by: Sarinamfgh on November 05, 2016, 08:55:43 am
For question 2, it says "the mass of peaches produced on this farm is known to be normally distributed with the variance of 16", and it wants the confidence interval for "all peaches", my interpretation was that a peach in this farm had the Sd of 4 not 4/5, seeing the answers my thinking is probably wrong, but can some one care to elaborate?
Many Thanks
Post by: zsteve on November 05, 2016, 09:43:57 am
Hey Guys,
For question 2, it says "the mass of peaches produced on this farm is known to be normally distributed with the variance of 16", and it wants the confidence interval for "all peaches", my interpretation was that a peach in this farm had the Sd of 4 not 4/5, seeing the answers my thinking is probably wrong, but can some one care to elaborate?
Many Thanks
Hi! The question states that the distribution of individual peach mass has a variance of 16, so the sd is 4. However, our sample size is 25, hence by the confidence interval formula:
\( [\bar{x}-M, \bar{x}+M] \text{ where } M = 1.96\dfrac{\sigma}{\sqrt{n}} \)
I.e. n = 25 here, hence we have \( M \approx 2 \dfrac{4}{\sqrt{25}} = 2 \dfrac{4}{5}\)
Post by: witmax33 on November 05, 2016, 02:49:46 pm
Post by: jazzycab on November 06, 2016, 05:30:30 pm
Would I lose any marks if I forgot to write m/s in my answer for Q8a and Q8b?
No marks lost, as the question specified the units. You only need to give the value (in the appropriate units)
Post by: BNard on November 06, 2016, 09:10:34 pm
Do you reckon there's any chance of scraping into a 30 ss with 91/100 sacs (rank 1 in weak cohort), C for exam one and B-B+ exam 2?
Post by: guest123 on November 06, 2016, 09:14:56 pm
Hey amigos,Jees how easy were your sacs
Do you reckon there's any chance of scraping into a 30 ss with 91/100 sacs (rank 1 in weak cohort), C for exam one and B-B+ exam 2?
Post by: BNard on November 06, 2016, 11:24:52 pm
Jees how easy were your sacs
Yeah they were way too easy - I think our teacher was trying to be nice.
Post by: Thunder8621 on November 10, 2016, 03:28:05 pm