Suggested Answers and Discussion for Specialist Exam 1

[decentxion]

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.....

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.

[Syedali_]

So i used g and got 156.8N

[decentxion]

So i used g and got 156.8N

That 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.

[Syedali_]

Why 5/4 and not 4/5

[keltingmeith]

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.

[Syedali_]

So i got 156.8 N and im pre surre its the way it should have been done , If you can explain sure

[keltingmeith]

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.

[hahahaliao]

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!

[Sarinamfgh]

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

[zsteve]

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 \( M \approx 2 \dfrac{4}{\sqrt{25}} = 2 \dfrac{4}{5}\)

[witmax33]

Would I lose any marks if I forgot to write m/s in my answer for Q8a and Q8b?

[jazzycab]

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)

[BNard]

Hey amigos,
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?

[guest123]

Hey amigos,
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?

Jees how easy were your sacs

[BNard]

Jees how easy were your sacs

Yeah they were way too easy - I think our teacher was trying to be nice.