# CSSA trials physics (1 Viewer)

#### Nosviper

##### Member
The Gravity for Jupiter
Im pretty sure i got 20 something Newtons ( i think 22N??)
I used the formual Gm/R(squared) i think. Since gravity of the body is proportional to the mass and inversely proportioanl to the square of the radius.

#### Nosviper

##### Member
yeh that escape velocity question with the 3.27J was quite stupid. I also go 1x10 (-17) meaning when I subbed it into the equation I got a velocity of like 0.0005ms or something which is obviously wrong. I think i changed it and got 3696ms or something.

#### Chinmoku03

##### Ippen, Shin de Miru?
Nosviper said:
I spoke about television CRT ect , integrated circuits, electrons in transistors/triodes, miniturisation of electrical equipment = faster processing time,

That 6 marker was fucked what did u get as the original velocity. I think i got 30 something ms-1) i wrote some crap for the 2nd bit but didnt come to an answer hopefully get some marks for working. The rest was ok. They asked too many space questions and focuesed on one area which sucked.
IIRC, the range was 72m and the time of flight was 4.06s? So I used s = ut + 0.5at2, sub'ed in s = 72 and t = 4.06, then rearranged in terms of u, which turned out to be 17.734ms-1. The second part, I had no idea how to prove that it was the same rocket. (Was it even the same rocket? O.O; Did anyone work out the question?) I bullshit'ed about something like assuming that they are the same rocket, then the time at which the 2 rockets reach a horizontal displacement of 50m would be the same and proved that the times were the same, therefore they were the same rocket :S

Wow, you wrote so much for the electron manipulation question O.O I don't think I would have enough space to write all that >.<; I hope focusing on just the TV won't make me lose too much. But the question did say discuss, which meant you're spose to give detriments too, right? What did you write for that? o.o

also, wot was the gravity on the surface of jupiter!!!!????
What you do is equate F = ma with F = (Gm1m2)/r2, let the m's cancel, which would make a = Gm/r2. Sub in the values and solve for a.

I agree that some of the values were outrageous. It's almost like I was doing maths in YR5 again... "If a basket can hold 1 x 109 oranges, how many baskets are needed for 5 x 109 oranges?" Me: "That's a pretty damn big basket you've got there... -.-;"

#### Ozza

##### Member
Lol sorry, I'm independant and did mine last week... but what did the second question of the six marker ask?...

Just out of curiosity.

#### Chinmoku03

##### Ippen, Shin de Miru?
IIRC, you're given the range of rocket A as 72m, its time of flight to be 4.06s and its initial angle to the horizontal to be 48o.

Then, rocket B makes an angle of 22o with the horizontal when its horizontal displacement is 50m.

The question was to show that rockets A and B are in fact the same rocket, given that both rockets are ideal projectiles. Not sure on this tho; Maybe it asked us to show they aren't the same rocket instead, can't remember. Can someone fill me in? >.<;

#### Pastafarian

##### New Member
joey89e said:
omgg physics was soo confusing 2dayy .. does anybody have any
the eddy current one - how to reduce the heat??? i rote about laminted iron core.. but thats all i had - not enough for 3 markss... wat were we supposed 2 do???
Holes and specific shape, etc.

#### jason21

##### Member
was it just me or did anyone else notice the poor use of english in some of the questions.

#### imraan7860

##### New Member
hmmm very hard trial, lol, i reckon i did alrite tho

Projectile - shit this was hard, but i think i got it, dude up there which i forgot ur name, it was prove they are consistent, i wrote assuming table one is true, i used the angle of 22 degrees to find Vy then found time, then subbed it back into range equation to get 50m, hence true, i gopt 48.6 but yeh if teacher marks me down for that ima slap him silly

Escape Velocity - did everyone else get a fkn smaaaaaaall number, i was like wtf, cause i didnt noe whether it was escape from earth or esacpe from the position it was as described in the question, which is like miles away form earth

Gravity jupiter - i got 25 i think

Everyhting else was alrite i guess, i stuffed up some diagrams, but yeh i noe wat i did wrong

#### Chinmoku03

##### Ippen, Shin de Miru?
I spose you mean me. What you did sounds like it's similar to what I did, so I hope you're right, for the both of us ^.^;

Some multiple choice questions I found difficult: Q6, the one about inducing 8 microamps in a coil. Does anyone know the right formula to use for this? I tried both emf equations, but neither seemed to work.

Also, Q9, (IIRC... <.<; ) the one about what kind of current the generator with the slip rings produce, I know it's AC, but one option had the AC starting from negative and another option starting from the positive. Anyone know the answer for this? >.O;

#### shut up

##### ruler of all
killed all the extended responses but screwed up every single calculation in there..... the wording of the questions was tricky as, half way down the manipulating electrons page i realised i wasnt answering the question - its was what new technolgies came out of manipulation, not what technology did
ah well. its over!!!! and this is the very very very last time my mother marks my assessment and pulls me down because she knows when im bullshitting

#### wrxsti

##### Rambo
shut up said:
killed all the extended responses but screwed up every single calculation in there..... the wording of the questions was tricky as, half way down the manipulating electrons page i realised i wasnt answering the question - its was what new technolgies came out of manipulation, not what technology did
ah well. its over!!!! and this is the very very very last time my mother marks my assessment and pulls me down because she knows when im bullshitting
my escape velocity was very low.... units were in m/s i got somefing lik 0.0089m/s i repeated it lik a million times and got same answer.......
im guessing cause the Gravitational Potential Energy was so low..... an escape velocity would be ridiculously low as well....

#### denoz

##### Member
I'm pretty sure i got something like that as well

#### jason21

##### Member
yer the gravitationl potential energy was 1.0x10^-17 so the escape velocity wouldve been something like 0.003ms^-2

#### mitosis

##### New Member
Anyone got an explanation for the correct answer to mc q9 on the cssa trial?

#### perry1989

##### New Member
joey89e said:
omgg physics was soo confusing 2dayy .. does anybody have any idea wat the 1st projectile question was asking???? i found the speed .. but wat was the 2nd question saying ... also...

the eddy current one - how to reduce the heat??? i rote about laminted iron core.. but thats all i had - not enough for 3 markss... wat were we supposed 2 do???

how did everyone else findd it??
i totally agree with you. i couldnt get the projectile question at all. i spent so long on it. it seems other people did aswell.
and i only put laminating the core for the eddy current question aswell.
i nailed my medical physics i reckon.
overall i estimate 50% lol =[

#### Nosviper

##### Member
Got the CSSA trial back today. Went pretty well with 80/100. Made some stupid mistakes but came 2nd. Top mark was 84/100 but maybe i will get 1st overall depending on overall marks.

94 physics

#### shut up

##### ruler of all
wrxsti said:
94 physics
please tell me you go to james ruse! ill be nice. freak. freak. hate you ( no, not reaaaallly)
i screwed up that exam soooo bad.. think r highest mark was 84, so there goes my ranks as 1st.....

#### wrxsti

##### Rambo
actually i dont go James Ruse..... i go to a pretty low ranked school actually......
our highest UAI to date has been 93..... so dat pretty much sums up our school performance.... except all teachers now are telling me they have faith that i can get the first 99 :S:S:S lol PRESSURE !

#### joey89e

##### Senior Member
wrxsti said:
actually i dont go James Ruse..... i go to a pretty low ranked school actually......
our highest UAI to date has been 93..... so dat pretty much sums up our school performance.... except all teachers now are telling me they have faith that i can get the first 99 :S:S:S lol PRESSURE !
ur pretty smart mate...i wish i was more like u