General Thoughts: Physics (3 Viewers)

[Dx_God]

Re: 2009 HSC Physics - How did you go?

i think ure looking too much into the question, i think their looking for u to say that g cant be sheilded, hence C is correct

its a concept question which i put down c first as well but i changed it due to the hard fact i thought of in my mind. consider the case where no earth exist. the force would b only caused due to gravitational attraction. now u put earth in the middle. if c was 2 b correct then ur saying earth does not apply a force on either sun or the moon as the force is constant and hence ur saying newton's theory is totally wrong. so ur basically challenging newton, the greatest sciencest ever and his work. if u still want to say c is correct then u have 2 abolish the whole newtonian physics and it will mean sun would not exert a force on the moon in the first place. if bos said c was the correct answer then i would simply ask them r they saying newton is wrong coz it comes down to tat matter. (and yea i'm a freak at physics) (though newton was abit wrong at his law of universal gravitation but tats only if u take in extremities which is explained by einstein and his general relativity in uni which i have already learnt and i'm yr 12 just 2 make things clear)

 

[untouchablecuz]

Re: 2009 HSC Physics - How did you go?

i dont understand how 3 C is not correct

its the only one that makes sense in the context

 

[EgyptianKing]

ummm teslas are always low, (earths magnetic feild=0.5 teslas, mri machine feild = 2 teslas) but i think i got a few more zeros in there im not sure but i think my answer was
0.000256 telas, maybe, definitly had 256 in there though

Yeah i got that, i also thought it was small, but left it as is it because im pretty sure my calculations were correct

 

[clonestar]

Re: 2009 HSC Physics - How did you go?

Q 3 and 5 are very poor questions.

I am sticking with 3 - D as gravitational field is the geosynchrous orbit and infinity to Geo and infinity to higher orbit (difference) is the work done. Even though they did not state the difference they infer it in the question.


Q 5 I am still scratching the head...if you compare it to a solar eclipse the moons position is much closer to the sun hence the force is greatest. As a consequence comparing the two from solar to lunar the force of the sun on the moon goes from maximum to minimum...??? NFI

 

[untouchablecuz]

Re: 2009 HSC Physics - How did you go?

for 5 i got C

cause the graviational field of the Sun remains the same; doesn't it

 

[M@ster P]

706 light years or something like that

I have no idea with the light year question, im pretty sure i did it wrong, this is what i did.

I did T = d/s

d = from previous question the distance of earth to the galaxy in the spaceship's frame of referecnce

s = 0.9999C

then i calculated T , is this correct?

 

[Dx_God]

lol mc is mostly concept based which is y i'm so excited coz i know other ppl r going 2 stuff up XD. (i'm evil =))

 

[08joel08]

i thought i owned that test, most of my unsure calculations have been confirmed and was close to performing sexual acts to med physics (not literally)

the only mark i know i couldnt have got was the question on rubber bands and their stretching being relative to weight or something, it didnt seem to make sense, can anyone explain???

 

[M@ster P]

got around 75 which is ok, should be band 5 aligned

 

[M@ster P]

i thought i owned that test, most of my unsure calculations have been confirmed and was close to performing sexual acts to med physics (not literally)

the only mark i know i couldnt have got was the question on rubber bands and their stretching being relative to weight or something, it didnt seem to make sense, can anyone explain???

is this the second part of the question asking you to find values of the extension which is proportional to mass? then it is just a straight line, i got m between 1 and 3

 

[slamduncs]

is this the second part of the question asking you to find values of the extension which is proportional to mass? then it is just a straight line, i got m between 1 and 3

It was from 0 > 1.3

 

[4theHSC]

Reckon it was hard, not very but managable, option was ok,, but I hated the paper

 

[Kid B]

I know its probably straight forward but how did u calculate the magnetic field on side X of the coil on the one with the rock?

 

[EgyptianKing]

is this the second part of the question asking you to find values of the extension which is proportional to mass? then it is just a straight line, i got m between 1 and 3

yeah i got between 1 and 3 too, I wasnt sure if it was exactly 1 though, might of been alittle further where it just bent alil, but oh well

 

[slamduncs]

I know its probably straight forward but how did u calculate the magnetic field on side X of the coil on the one with the rock?

F=BIL or T=BIA/2 both gave me the same answer.

 

[08joel08]

I know its probably straight forward but how did u calculate the magnetic field on side X of the coil on the one with the rock?

i used t=BIAcos@ but was unsure when i finnished, it made sense that that would give the answer though so i left it at that

i think i might have used t=fd to find the torque too, were u given torque in the quesiton?

 

[biopia]

OMG. My "doubt marks" are all being confirmed!!! Man, I love this site
Now, I am hoping for at least a 93

P.S. I had no idea the physics band 6 cut off was high 70's, low 80's. Just like I didn't know the cut offs for maths etc. Where do people get this information from lol???

 

[clonestar]

Re: 2009 HSC Physics - How did you go?

i dont understand how 3 C is not correct

its the only one that makes sense in the context

It is NOT correct as the work done is from infinity to those points. In that answer the assumption is horses for courses and could possible refer to zero as the centre of earth.

Either way whoever wrote those answers has no clue how to write proper English. The real answer is the a bit of C and a bit of D as C has the word "difference" stated the correct part but fails to mention from infinity... whilst D states a very large distance away but fails to mention geosynchronous and difference.

What a crap of a question... and then A comes in and possibly based on correct terminology could be the BEST answer... LOL but C and D is where it should have been.... arghhhhhhhhhhhh :burn:

AMBIGUOUS MC answers NSW BOS - PHYSICISTS SAY NO!!!!!

 

[Kid B]

F=BIL or T=BIA/2 both gave me the same answer.

I dont really remember the question too well but how did u get F?

 

[Dx_God]

Re: 2009 HSC Physics - How did you go?

wat i was thinking was wouldn't earth attract sun and sun attract earth and wouldn't the moon attract the earth and the earth attract the moon. so shouldn't the sun move towards the earth abit and moon also move towards the earth abit and reducing the distance and increasing the force.