Suggested Answers and Discussion for Specialist Exam 1

[brenden]

These answers were prepared by Samuel Chee of Derrick Ha Student Coaching Services!

[angrypotato1]

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

[Jemin99]

It was comparable to last years one, slightly easier maybe
What is your prediction of A+ cutoff?

[Maths Forever]

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? 

[brenden]

Would you have a copy of the paper by any chance? 

Not yet

[jazzycab]

Done this quite rushed, so possibly some errors.
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)

[Jemin99]

Done this quite rushed, so possibly some errors.
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)

Question6 its 4+4root3i

[shlblk]

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?

[Dumi]

Would I get consequential marks for the last one? I did the antidiff wrong but everything after that right.

[brenden]

Done this quite rushed, so possibly some errors.
Here are my answers only:

Do you have a copy of the exam?

[StupidProdigy]

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?

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!
edit: thought you had 24.5 and used g=10, ignore what I said

[shlblk]

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.

[angrypotato1]

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

[shlblk]

Also for the speed, I left it as root(16 + 20Cos2(t)) and not 2root(4 + 5Cos2(t)), would I lose marks for that?

[BNard]

Anyone have a rough idea of the mark allocations?