Adding subjects that aren't showing/Physics Chatter

[simpak]

Hey why are you doing physics though?  Because it's a prereq or because you wanted to test the waters, try it out etc?
If it's a prereq you may as well stay, you're half way through almost it is week 5 so like, next week you are halfway through.

People who take this subject - did we ever actually do gravity?  I kind of didn't keep up with the work while I was trying to understand the stuff we needed to know for the test and now I can't remember if we were going to 'talk about gravity later on' when we were doing orbits or if we actually did it but I can't remember Sevior making puns about apples and heads with his crazy grin and I'm almost SURE that would have happened.
Alternatively, I was asleep.
Anyway, have we gone through it in class yet?  I just got up to it in the textbook and while I vaguely recall discussing orbits I do not remember the gravity stuff.

[simpak]

OH MY GOD LOL I JUST FOUND SLIDES ON IT SO WE MUST HAVE DONE IT...this is like a black hole in my memory.

[schnappy]

All my research and intuitive has lead me to believe there are quite a lot of jobs for physics students. As teachers.

Other than that, engineering is where it's at. That's what I'm looking at doing Quantum mechanics and all that looks cool, but I don't really like obscure mathematics anyway.

[John President]

anyone doin physics advanced?..how do ull find that lecturer?david jamison is it?...IMO hes not at al good at explaining sme concepts..TB is way better

David Jamieson is amusing at times and is clearly passionate about what he does but makes everything seem more complex, not simpler. It's frustrating when he goes off on some random tangent about advanced subatomic physics that goes way over everyone's heads.

Planning to "downgrade" next semester.

[simpak]

Lol, 16.5/18 on the Fundamentals test <- ROCK.

[happyhappyland]

16/18!

[simpak]

16/18!

We are going to fucking own this subject.

[schnappy]

Anyone here in Physics 1? The assignment is damn easy, but Q4 Part E... is something missing from the question? Does it mean the work done from h=200 to h=0? (ie. bottom of the incline) It doesn't say to find the work over an interval of w/e...

[Elnino_Gerrard]

How are peopl going in the advanced assingment?? the flywheel question wtf?..the only thing i could find wrong was turning?? anyone else think so as well?

[schnappy]

Hmm slight problem on the Physics 1 assignment - Q4 Part G.
Work = F*x
Work = T*x
T=Mg*sin(angle of counter mass)
for me x is 400m...
Then make it negative for direction. And I'm getting the wrong answer apparently - used 2 of my goes!

[Blakhitman]

yea this assignment is screwed, for the net work question, I put in 0 so I get more attempts (collectively) that way (depends on part g) and it was correct...but the thing is moving so it makes no sense.

Then again I did the screwed up one before it was updated don't know if it was one of the errors or if it does make sense...

meh I got 96% and it's only worth 5% so I don't really care if it screwed me up.

[schnappy]

Knowing that the net work is 0, I work back and I get a different value for the cable's work (took a leap and put this asnwer in - got it right. Thank fuck). sigh.

How did you work out the work done by the cable? If you don't want to tell me that's ok. [Got 98% for this question. Most errors were subbing in numbers wrong, using the wrong sign 'cos i worked things in my head differently... MasteringPhysics is a royal pain in the arse]

For question 5, i had huge problems getting the right numerical answers... turns out when i did ans/2pi on my calc, it divided by 2 then multiplied by pi. I just ended up using an online rpm -> rad/s and vice versa calculator to do it. Made it easy, but then i lost 0.14% because of sig figs. 0.14%. Really? 0.14%...

Q3 is odd. Part B... it says in terms of a b A etc. but then when i exclude a (i'm yet to see where a is relevant) it tells me that the equation shouldn't have b... hmmm I'm still stumped. Energy = mg(b+A) is wrong, probably mg(a+A) but I want to be convinced before i say it is.

Could someone doing Adv. Physics post up one of their questions? Just curious to see what it's like.

[Elnino_Gerrard]

There you go

[Blakhitman]

Needed to put the 2pi in brackets. You lose a small percentage for each attempt used I'm pretty sure, I don't think you lose for sig figs.

Yea part B the answer is: mga + mgA....which is stupid, because i think it should just be mgA. the ball is at height A from where GPE is 0 and it's the only mass there. the pan is massless so mga=0, and I don't know why there both m, they're different masses and there's only one ball, arrggggghhhh it pissed me off. but I guessed it when I got it wrong and got the rest right. You're right "a" has no relevance because only the pan is at "a" and it is massless!!!

/end rant

[schnappy]

Thanks. Interesting, you guys have an assignment similar (identical really) to past Physics 1 assignments. Ours is just problem solving on MasteringPhysics :S

Not as difficult as I thought advanced would be, considering comments I've seen in the past.

@Blakhitman
Yeah I figure it needs to be in brackets... fairly bad logic I think though. If i wanted to divide by 2 then multiply by pi, i'd have written ans*pi/2.

I don't follow. The question is badly written I'll give you that, first time I read it I had absolutely no idea what was going on. The clay ball is dropped from the ceiling, where grav pot = mgh. h is the distance from the maximum extension of the spring + a to the ceiling (as the question defines), since a is rest length of the spring. Makes sense to me now, I was thinking b because it'd be the equilibrium point for that... nvm.
Edit: Part C. energy at max extension should be the same as the initial energy (same as Part B). But now it involves variable b... WHAT!? - turns out it wanted it in strain energy form, so i could then equate the two.