ATAR Notes: Forum

Archived Discussion => 2009 => Mid-year exams => Exam Discussion => Victoria => Physics => Topic started by: Mao on June 08, 2009, 09:57:03 pm

Title: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 08, 2009, 09:57:03 pm
See attached
First document: AOS1, AOS2, Structures + Further Electronics Questions And Solutions
Second document: Special Relativity Questions and Solutions


Errata:

Q10 Electronics, Rtherm = 500 ohms [from graph]. Rv = 1000 ohms.
Title: Re: Space Reserved
Post by: mano91 on June 08, 2009, 10:13:58 pm
omg mao, i dont know if i wanna look at it!
Title: Re: Space Reserved
Post by: Mao on June 08, 2009, 10:17:58 pm
omg mao, i dont know if i wanna look at it!

that's entirely up to you :) I knew a few people who chose to avoid it [but they still did well anyways].
Title: Re: Space Reserved
Post by: kurrymuncher on June 08, 2009, 10:22:51 pm
No way am I looking at this. lol I couldnt sleep for days after looking at the solutions for methods last year.
Title: Re: Space Reserved
Post by: TonyHem on June 09, 2009, 09:07:15 am
No way am I looking at this. lol I couldnt sleep for days after looking at the solutions for methods last year.

Same for IT, so I'm gonna ignore this ;)
Title: Re: Space Reserved
Post by: Damo17 on June 09, 2009, 09:31:37 am
No way am I looking at this. lol I couldnt sleep for days after looking at the solutions for methods last year.

Same for IT, so I'm gonna ignore this ;)

But your not going to forget the last page this time.  :)
Title: Re: Space Reserved
Post by: dekoyl on June 09, 2009, 01:59:46 pm
I've got the exam here but not a scanner. Does anyone have a scanner and can upload the exam?
I doubt anyone wants mobile-phone photos of the exam.
Title: Re: Space Reserved
Post by: KeyMan on June 09, 2009, 02:13:35 pm
I've got exam and scanner, it'll take a while to scan and upload all of it at once. I should have it available by 3pm  :)
Title: Re: Space Reserved
Post by: enwiabe on June 09, 2009, 02:14:35 pm
Awesome, thanks KeyMan.
Title: Re: Space Reserved
Post by: KeyMan on June 09, 2009, 02:29:00 pm
Ok, I've got AOS1 scanned
Title: Re: Space Reserved
Post by: KeyMan on June 09, 2009, 02:36:18 pm
AOS2
Title: Re: Space Reserved
Post by: krzysiek on June 09, 2009, 02:53:52 pm
cheers, waiting for the rest :)
Title: Re: Space Reserved
Post by: KeyMan on June 09, 2009, 02:56:51 pm
AOS 3
Einstein - http://www.mediafire.com/?4dgmyjzek5j
Electronics - http://www.mediafire.com/?whmje0tmlwm
Structures - http://www.mediafire.com/?kt4cnzjjman

Enjoy :)
Title: Re: Space Reserved
Post by: dekoyl on June 09, 2009, 02:58:30 pm
I broke into my sibling's room for the scanner and was half way done. Ah well :P

Thanks Keyman and Krzysiek
Title: Re: Space Reserved
Post by: junkie1999 on June 09, 2009, 03:05:22 pm
http://www.itute.com/board/viewtopic.php?f=6&t=872

I think I got all those, except for Q 8 I got 720N
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 03:07:39 pm
Here's my answers, is this what you guys got?

AOS1
1. 2.67
2. inelastic, initial kinetic energy does not equal final kinetic energy
3. 2560
4. Arrow to centre of circle
5. 500
6. 1.25
7. 600
8. 480
9. (Can't remember exactly what I wrote) Apparent weightlessness occurs when the only force acting on an object is due to gravity. The object feels no normal reaction force, hence it feels "weightless" etc etc
10. 45
11. 135
12. 8.37
13. Arrow pointing to centre of earth
14. 15260

AOS2
1. 4.29
2. 0.82
3. 0.23
4. 0.05
5. OFF OFF OFF ON ON ON
6. 300
7. Clips when V_in is 30mV , inverted
8. B, A, C, B
9. 5000
10. 1000
11. increased

Structures:
1. D
2. D
3. A
4. D
5. D
6. B
7. B
8. D
9. A
10. D
11. C
12. C
13. C
Title: Re: Space Reserved
Post by: Over9000 on June 09, 2009, 03:09:11 pm
all same except I did 720 instead of 480 for weight question  :tickedoff: :tickedoff: :tickedoff:
Title: Re: Space Reserved
Post by: Damo17 on June 09, 2009, 03:10:01 pm
all same except I did 720 instead of 480 for weight question  :tickedoff: :tickedoff: :tickedoff:

A few people from my school did that as well. I wrote 480N.
Title: Re: Space Reserved
Post by: junkie1999 on June 09, 2009, 03:11:56 pm
Since it is going up at 5m/s, then deccelerates at 2m/s/s the acceleration would be in the downward direction, same as the acceleration due to gravity. Adding these together gives an acceleration of 12m/s/s which results in a weight of 720N.  I hope that's right
Title: Re: Space Reserved
Post by: danieltennis on June 09, 2009, 03:19:32 pm
Since it is going up at 5m/s, then deccelerates at 2m/s/s the acceleration would be in the downward direction, same as the acceleration due to gravity. Adding these together gives an acceleration of 12m/s/s which results in a weight of 720N.  I hope that's right

I just got
Fnet = mg - N
60 * 2 = 60 * 10 -N
N = 480 N

And also you know that the Normal reaction force must be smaller than the  previous q because Fnet is downwards since its decelerating. Therefore, W > N
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 03:19:41 pm
Since it is going up at 5m/s, then deccelerates at 2m/s/s the acceleration would be in the downward direction, same as the acceleration due to gravity. Adding these together gives an acceleration of 12m/s/s which results in a weight of 720N.  I hope that's right
Let up be positive




Title: Re: Space Reserved
Post by: Over9000 on June 09, 2009, 03:20:23 pm
Since it is going up at 5m/s, then deccelerates at 2m/s/s the acceleration would be in the downward direction, same as the acceleration due to gravity. Adding these together gives an acceleration of 12m/s/s which results in a weight of 720N.  I hope that's right
Omfg, that exactly my thinking, but then I realised im pretty sure its wrong, the answer is 480N im sure, sigh, I suk at logic
Title: Re: Space Reserved
Post by: appianway on June 09, 2009, 03:31:47 pm
It's definitely 480 N.

Obviously I don't have my exam here with me, but I think all of my answers were the same as the iTute ones... I might be getting a derived score anyway though, but it's a relief to know that I didn't fail.

Still annoyed at the simplicity of the exam though.
Title: Re: Space Reserved
Post by: NE2000 on June 09, 2009, 03:42:02 pm
480 is right...

Does anyone know why the projectile question gave a page of working and was worth four marks?
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 03:45:43 pm
480 is right...

Does anyone know why the projectile question gave a page of working and was worth four marks?
No idea, teacher said it was ridiculous.
Title: Re: Space Reserved
Post by: hauhau on June 09, 2009, 03:45:58 pm
what was question 12 for AOs1 again?
Title: Re: Space Reserved
Post by: NE2000 on June 09, 2009, 03:47:50 pm
what was question 12 for AOs1 again?

Vertical circular motion

N=0

Find v
Title: Re: Space Reserved
Post by: Damo17 on June 09, 2009, 03:48:51 pm
what was question 12 for AOs1 again?

Vertical circular motion. Min speed at top when inside loop.

Working:
10=v^2/7 , v=8.37
Title: Re: Space Reserved
Post by: hauhau on June 09, 2009, 03:51:41 pm
tks... i think i got 90 xD
Title: Re: Space Reserved
Post by: danieltennis on June 09, 2009, 03:52:16 pm
480 is right...

Does anyone know why the projectile question gave a page of working and was worth four marks?

just reminded me of the q that required you to draw a simple graph in the methods exam 1 last year. It was also worth four marks.

Edit: 1000 POSTS. IM part of the VN furniture
Title: Re: Space Reserved
Post by: methodsboy on June 09, 2009, 03:53:29 pm
hmm according to the solutions, i should get about low A+ to high A.
Title: Re: Space Reserved
Post by: dejan91 on June 09, 2009, 03:57:32 pm
Don't you hate it when you know you were thinking of the right answer but you didn't know it at the time? So you put the wrong one...Or is that just me?
Title: Re: Space Reserved
Post by: appianway on June 09, 2009, 03:58:21 pm
I'm really interested in what the cut off for an A+ will be/how many 90s will be obtained. I presume that a lot of people will overestimate their marks because they don't know their answers to the MC off by heart, or will assume that they scored perfect marks on the explaining questions.
Title: Re: Space Reserved
Post by: TonyHem on June 09, 2009, 03:58:35 pm
Lame.. I had the right answer for that projectile motion one and changed it >_>
That's what I get for trying something new on the exam lol
Title: Re: Space Reserved
Post by: methodsboy on June 09, 2009, 03:58:50 pm
Don't you hate it when you know you were thinking of the right answer but you didn't know it at the time? So you put the wrong one...Or is that just me?
OMG yes!...i fcuked up that sum of all torques at P.....hgskja teity sa !
Title: Re: Space Reserved
Post by: NE2000 on June 09, 2009, 03:59:12 pm
I'm really interested in what the cut off for an A+ will be/how many 90s will be obtained. I presume that a lot of people will overestimate their marks because they don't know their answers to the MC off by heart, or will assume that they scored perfect marks on the explaining questions.

But weren't there just two explaining questions?
Title: Re: Space Reserved
Post by: appianway on June 09, 2009, 04:05:38 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
Title: Re: Space Reserved
Post by: kenny17 on June 09, 2009, 04:07:10 pm
can anyone tell me exactly wat to clik to get the solutions??
Title: Re: Space Reserved
Post by: Damo17 on June 09, 2009, 04:11:05 pm
can anyone tell me exactly wat to clik to get the solutions??

http://www.itute.com/board/viewtopic.php?f=6&t=872
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 04:12:40 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
2 points for what...?
Title: Re: Space Reserved
Post by: NE2000 on June 09, 2009, 04:13:46 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
2 points for what...?

For weightlessness question, 4 points for 4 marks.
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 04:15:36 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
2 points for what...?

For weightlessness question, 4 points for 4 marks.
Teacher said for that question, 1 point = 2 marks.
Title: Re: Space Reserved
Post by: NE2000 on June 09, 2009, 04:17:07 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
2 points for what...?

For weightlessness question, 4 points for 4 marks.
Teacher said for that question, 1 point = 2 marks.

Oh well...all that means is that a lot of people might have overdone their explanations but it won't cost them anything as long as it's all correct.
Title: Re: Space Reserved
Post by: naved_s9994 on June 09, 2009, 04:17:34 pm
for q 8, AOS 1 - dont we use m(g+a)...= 720?
everyone including teachers said that.
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 04:18:29 pm
for q 8, AOS 1 - dont we use m(g+a)...= 720?
everyone including teachers said that.
If you think about it intuitively, as you are slowing down in a lift, wouldn't you feel lighter? :X
Title: Re: Space Reserved
Post by: anonuser0511 on June 09, 2009, 04:20:39 pm
haha i was sitting there in an exam making elevator noises to get that one

i know i lost one on the LED, and perhaps one on the explanation of increase - since itute doesn't have it how did you guys prove it?
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 04:21:46 pm
Using voltage divider formula: (Say the temperature was , I think this corresponded to 5000 ohms of resistance for thermistor, can't remember exactly)

So R must increase if you still want to get 8V.
Title: Re: Space Reserved
Post by: kurrymuncher on June 09, 2009, 04:24:49 pm
arrrrrgh crap I only put two OFFs for the LED question.
Title: Re: Space Reserved
Post by: anonuser0511 on June 09, 2009, 04:25:29 pm
yea i put down voltage formula and subbed in random values
Title: Re: Space Reserved
Post by: danieltennis on June 09, 2009, 04:25:44 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
2 points for what...?

For weightlessness question, 4 points for 4 marks.

From memory:
- apparent weightless is experienced by an object when in free fall and moving with an acceleration equal to the gravitional field strength at their location
- there is no force between the object and its surroundings
- Hence, N=0
- Gravitational weight force will remain the same since W = mg. Mass and g stays the same

I wrote another thing, but i can't really remember.
Title: Re: Space Reserved
Post by: anonuser0511 on June 09, 2009, 04:26:12 pm
arrrrrgh crap I only put two OFFs for the LED question.
yea same. if only we lived in some sort of string theory universe where LEDs in forward bias can light up without a complete circuit...
Title: Re: Space Reserved
Post by: anonuser0511 on June 09, 2009, 04:28:07 pm
There were, but if people put down 2 points on one (rather than 4), then that's automatically a 88/90.. and so on.
2 points for what...?

For weightlessness question, 4 points for 4 marks.

From memory:
- apparent weightless is experienced by an object when in free fall and moving with an acceleration equal to the gravitional field strength at their location
- there is no force between the object and its surroundings
- Hence, N=0
- Gravitational weight force will remain the same since W = mg. Mass and g stays the same

I wrote another thing, but i can't really remember.

i went with
-not experiencing true weightlessness as
w=mg
g>0
W>0

then
Fnet = mg - N
ma = mg - N
N = mg - ma
in freefall (a=g)
N = m(0)
   = 0
then i had some random example of here pulling something out of her pocket it'd appear to be floating
Title: Re: Space Reserved
Post by: IntoTheNewWorld on June 09, 2009, 04:30:46 pm
Reading answers is so depressing =x
Title: Re: Space Reserved
Post by: dejan91 on June 09, 2009, 04:31:35 pm
arrrrrgh crap I only put two OFFs for the LED question.
Yeah screwed me up too. * Facepalms* But after you think about it, it MUST turn off as there isn't a complete circuit in that part of the parallel circuit. Pretty much the equivalent of cutting the wire at the reverse-biased LED.
Title: Re: Space Reserved
Post by: simplicity123 on June 09, 2009, 04:32:02 pm
how many marks do u think i'll lose if i put 720N for that apparent weight question. Im pretty sure my method was all right except that i misinterpreted the 2ms^-2 decelerating and used -2 instead, thus resulting in 720.

And with the explanation of the apparent weightlessness, i also gave an example of a body falling downwards, saying that the only forces acting on it are gravitational force and air resistance with 0 contact force. Isit ok if i said air resistance? Or does apparent weightlessness only mean gravity acting on the body only?
Title: Re: Space Reserved
Post by: dejan91 on June 09, 2009, 04:34:04 pm
Apparent weightlessness is when the acceleration of a body is that of gravity. i.e. in free fall. Air resistance is a resistive force, so having it will mean you're NOT falling at g ms^-2.
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 04:37:12 pm
how many marks do u think i'll lose if i put 720N for that apparent weight question. Im pretty sure my method was all right except that i misinterpreted the 2ms^-2 decelerating and used -2 instead, thus resulting in 720.

And with the explanation of the apparent weightlessness, i also gave an example of a body falling downwards, saying that the only forces acting on it are gravitational force and air resistance with 0 contact force. Isit ok if i said air resistance? Or does apparent weightlessness only mean gravity acting on the body only?
It is meant to be -2?
Title: Re: Space Reserved
Post by: simplicity123 on June 09, 2009, 04:41:19 pm
i assigned negative as upward force and weight as downward. You think they'll just take a mark off for that?
Title: Re: Space Reserved
Post by: TrueTears on June 09, 2009, 04:43:23 pm
question was worth 3 marks.

2 for working out.

1 for answer in the box.
Title: Re: Space Reserved
Post by: Mao on June 09, 2009, 04:47:21 pm
Apologies for the delay [had to go to VicRoads... =S ]. First post has been updated. Paper + solutions attached, Special Relativity solutions will be coming later tonight
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: IntoTheNewWorld on June 09, 2009, 04:52:38 pm
I dispute Question 10 of electronics

Thx heaps for solutions btw =D
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: mano91 on June 09, 2009, 04:53:45 pm
omg mao, i dont know if i wanna look at it!
[/quote
See attached
(Structures + Further Electronics)

hey mao, i believe you did question 10 incorrectly for electronics.
you just mis-read the value of the resistor at 25 degrees.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: simplicity123 on June 09, 2009, 04:53:57 pm
same, I think you read wrongly off the graph. Rtherm at 25degrees = 500ohms, you wrote 1250ohms instead xD
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: ATM on June 09, 2009, 04:56:39 pm
Yea just from memory i'm pretty sure i got 1000 ohms for the variable resistor on question 10
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 09, 2009, 04:57:27 pm
The answer is 1000 ohms
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: danieltennis on June 09, 2009, 04:57:37 pm
Yea just from memory i'm pretty sure i got 1000 ohms for the variable resistor on question 10

yeah.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: ATM on June 09, 2009, 05:00:01 pm
woot im gunna go party now
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 05:02:48 pm
ahaha, oops. I read the temperature as 15 degrees. >.>
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: jujimufu on June 09, 2009, 05:04:07 pm
The only things I messed up on were labeling the stupid arrows on the stupid "insert arrow showing the forces" questions grrrr, and one of the structures questions.. but apart from that.. YAYAYAYAYAYAYAYAYAYAYAYAYAY!!! and now to not study for chem! guitar hero awaits me..
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: ryley on June 09, 2009, 05:09:49 pm
Thanks for the solutions Mao, I'm so happy to see so many similarities in our answers.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: hxleong on June 09, 2009, 05:18:26 pm
*facepalm*
I changed my answer in the apparent weight thing from 480 to 720 cos I thought I got the formula wrong. fail

Otherwise HOORAY PHYSICS. easy exam
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kurrymuncher on June 09, 2009, 05:19:10 pm
crap lost 1 mark.. aww well
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TonyHem on June 09, 2009, 05:22:05 pm
Anyone know when we get our grades back from vcaa? ( letter grades)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dejan91 on June 09, 2009, 05:22:30 pm
I'm concerned. So many people claiming high scores...is that just because of the intellect of the people on this forum is wayyyy above average, or did the rest of VIC find it easy too?

And Tonyhem, apparently around August.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: mano91 on June 09, 2009, 05:26:07 pm
for the apparent weight question. i wrote 720. how many marks would i lose?
and also in the modulation question, i got 1 right.
is that a half mark?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: UprightMan on June 09, 2009, 05:26:39 pm
AHH *&!@.  I knew I got that loop de loop question wrong...but according to your suggested solutions Mao, I've done pretty well...Thanks heaps Mao!  Damn loop de loops...
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kurrymuncher on June 09, 2009, 05:27:32 pm
Im not sure about half marks, but your bound to get 1 or 2 marks for the apparent weight question, if you showed working
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 05:27:39 pm
I'm concerned. So many people claiming high scores...is that just because of the intellect of the people on this forum is wayyyy above average, or did the rest of VIC find it easy too?

You'll find that the people who have enough motivation to come to a VCE discussion site, actively participate in community discussion, help each other out and do things of that like, tend to be the better students of the state :)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 09, 2009, 05:28:45 pm
for the apparent weight question. i wrote 720. how many marks would i lose?
and also in the modulation question, i got 1 right.
is that a half mark?
I *think* you might lose 2 marks for the 720 question. Because 2 marks are for methods and 1 is for answer, the answer mark is consequential (meaning if your method is right but subbed in a wrong value, then even though your answer is wrong it still gets a mark, unlike other subjects like methods.) But if you get 720, it would mean your method had a problem as well.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dejan91 on June 09, 2009, 05:31:22 pm
I'm concerned. So many people claiming high scores...is that just because of the intellect of the people on this forum is wayyyy above average, or did the rest of VIC find it easy too?

You'll find that the people who have enough motivation to come to a VCE discussion site, actively participate in community discussion, help each other out and do things of that like, tend to be the better students of the state :)

Hmm I thought so. Anyway, thanks for the worked solutions Mao :)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TonyHem on June 09, 2009, 05:34:07 pm
For that question, I got 720 ( wrong), would I get a mark for doing:
Quote
Taking up as positive
Fnet = Fn+fg
Fn = 2 x 60 = 120
FG = 60 x -10 = -600
120 = Fn -600
Fn = 720

Based on those solutions, got the "h"value wrong and this q. :[
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: UprightMan on June 09, 2009, 05:34:23 pm
Did anyone get 100%?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 09, 2009, 05:37:24 pm
For that question, I got 720 ( wrong), would I get a mark for doing:
Quote
Taking up as positive
Fnet = Fn+fg
Fn = 2 x 60 = 120
FG = 60 x -10 = -600
120 = Fn -600
Fn = 720

Based on those solutions, got the "h"value wrong and this q. :[

I think you'd get 1/3 for that question.

You would have lost 1 for method, 1 for answer (since your answer was not consequential due to wrong method ; should have been )
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 05:43:45 pm
For the selected few who decided to do Special Relativity, the solutions are now up on first post.

Congratulations to all students, you have all survived Unit 3. :) [Rumour has it that unit 4 is easier]

I have referenced my solutions to Itute, everything is in agreement except where I didn't read the question properly. That has been corrected in Errata also in first post.

I will be happy to answer specific questions anyone may have. And I appreciate all those 'thank-you's being thrown around :)

Once again, congrats, and those of you who have chem tomorrow, toodles, go study :P
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: avram_grant on June 09, 2009, 05:45:40 pm
what do you guys reckon the average was? i reckon about high 60s, low 70s - generally the state makes silly errors
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 05:48:20 pm
For that question, I got 720 ( wrong), would I get a mark for doing:
Quote
Taking up as positive
Fnet = Fn+fg
Fn = 2 x 60 = 120
FG = 60 x -10 = -600
120 = Fn -600
Fn = 720

Based on those solutions, got the "h"value wrong and this q. :[

I think you'd get 1/3 for that question.

You would have lost 1 for method, 1 for answer (since your answer was not consequential due to wrong method ; should have been )

I believe he should get 2/3. The only mistake he made was he mistook a=-2 for a=2. Everything else were consequential.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: nbalakers24 on June 09, 2009, 05:49:09 pm
how long did it take you to wirte up the solutions Mao?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dejan91 on June 09, 2009, 05:49:17 pm
what do you guys reckon the average was? i reckon about high 60s, low 70s - generally the state makes silly errors
Well considering it was around last years difficulty (and the average was 64% last year), around 60-70% would be about right.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 05:49:50 pm
what do you guys reckon the average was? i reckon about high 60s, low 70s - generally the state makes silly errors

Overall, it wasn't a hard exam. The questions were fairly simple, but it was long. The state average should remain what it has in previous years, A+ cut off would be 10~14 marks.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 05:50:25 pm
how long did it take you to wirte up the solutions Mao?

With interruptions, ~1.5hrs
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kurrymuncher on June 09, 2009, 05:52:09 pm
10-14 marks?? thats way too much
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Damo17 on June 09, 2009, 05:53:35 pm
10-14 marks?? thats way too much

he means after doubling occurs, so between 83-85/90.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dejan91 on June 09, 2009, 05:54:11 pm
10-14 marks?? thats way too much

he means after doubling occurs, so between 83-85/90.

Doubling?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kurrymuncher on June 09, 2009, 05:54:25 pm
ahhk lol :P
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: redmosez on June 09, 2009, 05:57:09 pm
Thanks so much for the post Mao,

The only answer I'm confused about is question 11 in motion.

I figured the (total) max height of the parabolic path was 135, and to get the height of the cliff you had to subtract 45m from 135 to get 90m.

Can anyone please go through the question for?

Thanks again
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kurrymuncher on June 09, 2009, 05:58:20 pm
its 45 metres to go, and to go down it was 180m iirc, so the final height is like 180-45.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 09, 2009, 05:58:32 pm
Thanks so much for the post Mao,

The only answer I'm confused about is question 11 in motion.

I figured the (total) max height of the parabolic path was 135, and to get the height of the cliff you had to subtract 45m from 135 to get 90m.

Can anyone please go through the question for?

Thanks again
When you sub into the constant acceleration formula, the value of x you get is the displacement, therefore it already gives you the "h" value.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: redmosez on June 09, 2009, 06:00:51 pm
AH! it's so obvious now!

Oh well one wrong!

Thanks Truetears appreciate the quick reply mate
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: danieltennis on June 09, 2009, 06:02:57 pm
10-14 marks?? thats way too much

he means after doubling occurs, so between 83-85/90.

Doubling?

Two people mark the exam I think so its out of 180.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: purelemon on June 09, 2009, 06:04:44 pm
good luck to all doing chem! i know i need it :crazy2:
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Over9000 on June 09, 2009, 06:06:11 pm
good luck to all doing chem! i know i need it :crazy2:
Yes coz its assumed people doing physics are doing chem instead of people in the chem thread who are actually doing chem?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: purelemon on June 09, 2009, 06:07:44 pm
in case ppl really need the luck lol.....wow ur doin 6 subs in 09'?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Over9000 on June 09, 2009, 06:10:20 pm
in case ppl really need the luck lol.....wow ur doin 6 subs in 09'?
Yeh I dropped my 3/4 I was doing last year, and picked up one this year instead.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: purelemon on June 09, 2009, 06:17:48 pm
in case ppl really need the luck lol.....wow ur doin 6 subs in 09'?
Yeh I dropped my 3/4 I was doing last year, and picked up one this year instead.

btw u got a fukn problem with me doing 6 subjects?

lol so agro in yr 12 lol....take a chill pill...takin 6 subjects man....my hat goes off to you.. aside from italian im doin the same subs as u are...amazing some people can still cope to do more....RESPECT man

on a side note....DO U FUKN have a problem with me asking u why the hell u do 6 subs? lol
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Over9000 on June 09, 2009, 06:19:59 pm
WANNA GO ME!!!!!!!!!  :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff:
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: pHysiX on June 09, 2009, 06:20:58 pm
stupid apparent weightlessness thing. i have everything, just missed out that w=mg >.< i wrote something only kinda similar lol RAGE
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: mano91 on June 09, 2009, 06:37:19 pm
what do you guys reckon the average was? i reckon about high 60s, low 70s - generally the state makes silly errors

Overall, it wasn't a hard exam. The questions were fairly simple, but it was long. The state average should remain what it has in previous years, A+ cut off would be 10~14 marks.

you really think the cut off will be that low?
i mean, last years was 82/90.
i might be in luck if it is as low as u say :)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: BlueYoHo on June 09, 2009, 06:39:49 pm
aaaaaaah gayyyy!!!!! i lost ~3 marks... :(

lol im sorry to do this to you guys, but here goes:

If im averaging a "mid A" for the course work
and get an A+ for 1 exam
and A+ for the second exam...

what would my raw study score be?

lol sorry, couldnt resist, i just want to know.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 09, 2009, 06:41:14 pm
what do you guys reckon the average was? i reckon about high 60s, low 70s - generally the state makes silly errors

Overall, it wasn't a hard exam. The questions were fairly simple, but it was long. The state average should remain what it has in previous years, A+ cut off would be 10~14 marks.

you really think the cut off will be that low?
i mean, last years was 82/90.
i might be in luck if it is as low as u say :)
I think cut off will be around 85/90
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: redmosez on June 09, 2009, 07:05:45 pm
I wonder how many marks i'd lose for q's 11 in motion, i had all the working out right to get 135 but for some stupid reason I subtracted 40 right at the end.

Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 09, 2009, 07:10:45 pm
I wonder how many marks i'd lose for q's 11 in motion, i had all the working out right to get 135 but for some stupid reason I subtracted 40 right at the end.


Did you write in minus 40 in your working? Then put the answer?

If you wrote minus 40 in your working then put in answer, I'm guessing 1/3. (Since answer mark is not consequential)

If you didn't write minus 40 in your working and just put answer as 135-40, then you'd get 2/3.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: anonuser0511 on June 09, 2009, 07:14:45 pm
lol btw, was I the only one chuckling to myself in the gravity Q when radius = 1.33E7
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 09, 2009, 07:19:09 pm
lol btw, was I the only one chuckling to myself in the gravity Q when radius = 1.33E7

haha, lol
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: purelemon on June 09, 2009, 07:25:43 pm
WANNA GO ME!!!!!!!!!  :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff:

ill take u and those 3 henchmen of urs on in that sig of urs....u get those 3 i get chuck norris, bruce lee and clifford the big red dog
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Over9000 on June 09, 2009, 07:30:38 pm
WANNA GO ME!!!!!!!!!  :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff: :tickedoff:

ill take u and those 3 henchmen of urs on in that sig of urs....u get those 3 i get chuck norris, bruce lee and clifford the big red dog
Ill bring fox mccloud, u wont be able to move when he combos ur asse and edge guards u. Never mess with the fox
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: nbalakers24 on June 09, 2009, 07:36:13 pm
how long did it take you to wirte up the solutions Mao?

With interruptions, ~1.5hrs

nice work man.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: purelemon on June 09, 2009, 07:40:08 pm
lol ive got clifford the big red dog....with chuck norris at front with bruce lee at shotgun.....umm u forgot...u only have 3 henchmen cant have 4.....einteins relatvity wouldnt allow that cos fox's laser would not work appropriately according to those laws lol......anyways i need to study for chem this Arg is getting a little too complex for me

lol at the fail math pun
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: wingwong on June 09, 2009, 07:52:22 pm
what do you guys reckon the average was? i reckon about high 60s, low 70s - generally the state makes silly errors

Overall, it wasn't a hard exam. The questions were fairly simple, but it was long. The state average should remain what it has in previous years, A+ cut off would be 10~14 marks.

you really think the cut off will be that low?
i mean, last years was 82/90.
i might be in luck if it is as low as u say :)
I think cut off will be around 85/90
How about the cutoff for an A?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Over9000 on June 09, 2009, 07:57:35 pm
Whats the cutoff for NA?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: redmosez on June 09, 2009, 08:07:22 pm
I wonder how many marks i'd lose for q's 11 in motion, i had all the working out right to get 135 but for some stupid reason I subtracted 40 right at the end.


Did you write in minus 40 in your working? Then put the answer?

If you wrote minus 40 in your working then put in answer, I'm guessing 1/3. (Since answer mark is not consequential)

If you didn't write minus 40 in your working and just put answer as 135-40, then you'd get 2/3.

Nah I did all the working and got 135 then for some reason at the last minute wrote the answer as 90. I'm really hoping it's 2/3
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kaanonball on June 09, 2009, 10:19:03 pm
damn 5 marks gone! =(

i hope the cut off for an A+ is less than 85/90
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TonyHem on June 09, 2009, 10:50:37 pm
I wonder how many marks i'd lose for q's 11 in motion, i had all the working out right to get 135 but for some stupid reason I subtracted 40 right at the end.





Did you write in minus 40 in your working? Then put the answer?

If you wrote minus 40 in your working then put in answer, I'm guessing 1/3. (Since answer mark is not consequential)

If you didn't write minus 40 in your working and just put answer as 135-40, then you'd get 2/3.

Nah I did all the working and got 135 then for some reason at the last minute wrote the answer as 90. I'm really hoping it's 2/3

On one of the things some of the members uploaded here, it said that if the student has done all the right working out, shown that their final answer is correct but has somehow made a transfer error from the working out to the answer box, full marks "should" be awarded.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: tomygun_123 on June 10, 2009, 05:29:18 pm
according to this, i got all of the qstns correct except for 1 multiple choice and the 2nd elevator qstn... :)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: homghomg1 on June 10, 2009, 07:30:42 pm
Damn, Q11 from further electronics was my only mistake. Silly.
I'm 100% sure I wrote all that was required for all the explanation questions.
Hopefully I'm still in the run for a 50 with a 88/90
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: justin on June 10, 2009, 07:49:00 pm
Question 10, electronics is incorrect. It's not 1250 ohms. It should be 500.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TRoi on June 10, 2009, 08:05:08 pm
Question 10, electronics is incorrect. It's not 1250 ohms. It should be 500.
yeah true. And the answer is 1000ohms?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 10, 2009, 08:08:07 pm
Check Errata on first post :)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 10, 2009, 08:08:36 pm
Asnwer is 1000 not 500, if my memory serves me right.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: john316 on June 11, 2009, 04:55:15 pm
I should get 50.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dcc on June 11, 2009, 05:22:38 pm
How fast must a particle be moving such that its relativistic momentum is twice its newtonian momentum?

(and go.)
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dcc on June 11, 2009, 05:28:35 pm
and muons only stay alive for 2.2 * 10^(-6) seconds, i disagree with that question!
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Mao on June 11, 2009, 06:00:45 pm
How fast must a particle be moving such that its relativistic momentum is twice its newtonian momentum?

(and go.)

Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dcc on June 11, 2009, 06:07:44 pm
How fast must a particle be moving such that its relativistic momentum is twice its newtonian momentum?

(and go.)



that was almost as unsatisfying as when I got that question in my exam yesterday.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: ayaz on June 12, 2009, 06:32:07 pm
hey i was just wondering if you get (83/90) would that be an A+
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 12, 2009, 06:39:43 pm
hey i was just wondering if you get (83/90) would that be an A+

Stop double posting.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: rhjc.1991 on June 12, 2009, 07:08:17 pm
This exam was so weird. People I know who are smart are getting lower marks due to silly errors in Detailed Studies, which has TOO LITTLE questions for TOO MANY marks.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: ayaz on June 12, 2009, 09:23:31 pm
hey does any one have an approximation what might be the cut off score for an A+
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: methodsboy on June 12, 2009, 09:27:20 pm
hopefully 83/90
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on June 12, 2009, 09:32:18 pm
hey does any one have an approximation what might be the cut off score for an A+
Check other threads that you have posted in before you repost.

I think 84-85/90.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kurrymuncher on June 13, 2009, 12:39:49 am
hopefully 81/93


Thats too low, last years cutoff was 82. Since this years exam was easier, it wont move down. You mean out of 90 right??
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: dejan91 on June 13, 2009, 11:30:04 am
hopefully 81/93


Thats too low, last years cutoff was 82. Since this years exam was easier, it wont move down. You mean out of 90 right??

Hmm...Maybe everybody here just thinks it was easier than last year?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: NE2000 on June 13, 2009, 03:20:20 pm
This exam was so weird. People I know who are smart are getting lower marks due to silly errors in Detailed Studies, which has TOO LITTLE questions for TOO MANY marks.

Yeah it's a bit annoying that Physics MC are worth 2 marks each.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: Gloamglozer on June 13, 2009, 04:21:15 pm
hopefully 81/93


Thats too low, last years cutoff was 82. Since this years exam was easier, it wont move down. You mean out of 90 right??

Hmm...Maybe everybody here just thinks it was easier than last year?

I'm hoping that is the case as well, lol.  But I doubt that is the case.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: kashmuq on June 13, 2009, 07:05:21 pm
the A+ grade doesnt usually fluctuate that much for physics i dont think...probably going to stay low 80s
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: haggas on June 24, 2009, 10:50:28 pm
hey does any one have an approximation what might be the cut off score for an A+

high looks pretty easy
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: sebdog117 on August 28, 2009, 08:15:00 pm
thanks alot peeps, do u think next years test will be similar?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: NE2000 on August 28, 2009, 08:26:47 pm
thanks alot peeps, do u think next years test will be similar?

I think it will be lower. I think VCAA would want a better spread of results than they gained in this exam.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: IntoTheNewWorld on August 28, 2009, 08:29:54 pm
If it was easier...lol.

88 A+ cut off?
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: TrueTears on August 28, 2009, 08:31:24 pm
If it was easier 90 A+ cut off?

lol jk jk
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: NE2000 on August 28, 2009, 08:32:08 pm
lol I'm still waiting for the assessment report to come out to say how many full marks there were as the physics assessment report normally contains that information
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: NE2000 on August 28, 2009, 08:34:26 pm
If it was easier 90 A+ cut off?

lol jk jk

88 for an A?...lol...nah but I think VCAA will aim for a better spread of results and most likely will achieve it.
Title: Re: 2009 Physics Unit 3 Exam Suggested Solutions
Post by: IntoTheNewWorld on August 28, 2009, 08:35:35 pm
I hear it was a bit over 100. lol maybe they'll be too embarrassed to put it into the assessment report >_>