HSC Physics Marathon 2013-2015 Archive (1 Viewer)

[anomalousdecay]

Re: HSC Physics Marathon 2014

I meant d= distance travelled, not the torque. There is no rotation at all so I didnt mean torque. Other than that I don't know.
what about v= u +at ? do I use that?

Ok yeah you meant work.

Yeah some form of manipulation involves that, but you are really missing the key part of this question.

Think about relating forces to each other. That's pretty much how I approached this question from the beginning (actually pretty much how you approach many questions in uni physics).

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

Also, what direction does the wire travel in?

Show working for formula with a simple explanation of each part (dw about getting the actual value, just worry about getting the formula).

Sigh I'd expect any good students to know how to do this. This question is like something from Carrot's version of a MX2 paper except for Physics.

Its literally 2 lines if you know what's going on.

 

[Fizzy_Cyst]

Re: HSC Physics Marathon 2014

You are an evil one, AD! Give it a go padawans! It's not that hard! I promise the one that I will post after is harder!

 

[Fizzy_Cyst]

Re: HSC Physics Marathon 2014

/presses F5 repeatedly

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

Someone do answer. It would be a waste if I had to do it for everyone. If you have attempted it but got nowhere post in the thread and I can give hints. If no-one does it by this weekend I'll just put up the answer.

 

[Luckytree]

Re: HSC Physics Marathon 2014

is it just v=(tBiL)/m
subbing in all the values, 0.5m/s moving to the left?

 

[acronical]

Re: HSC Physics Marathon 2014

got same formula and answer here luckytree

 

[Fizzy_Cyst]

Re: HSC Physics Marathon 2014

Anyone for new question?

 

[mreditor16]

Re: HSC Physics Marathon 2014

Anyone for new question?

okay shoot

btw, emailed you back

 

[ClaudzSquiggle]

Re: HSC Physics Marathon 2014

Anyone for new question?

Well, I don't think he's coming back, so I'll ask one.

Why don't Maglev trains utilise the Meissner effect?

 

[IR]

Re: HSC Physics Marathon 2014

is it just v=(tBiL)/m
subbing in all the values, 0.5m/s moving to the left?

Almost feels likw you changed Fade1233 formula around to get 0.5 as an answer and now guess-and-ask.

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

is it just v=(tBiL)/m
subbing in all the values, 0.5m/s moving to the left?

Yeah that is correct.

Almost feels likw you changed Fade1233 formula around to get 0.5 as an answer and now guess-and-ask.

Well there is a systematic way to derive it.

F = BiL sin 90 = BiL

Also, the acceleration is characteristic of F = ma by Newton's 2nd Law.

So we obtain a = (v-0) / (t-0) = v/t = BiL / m (initially, velocity is zero as our reference)

Hence, v = BiLt/m


Pretty much everything you do in uni physics will involve systematically deriving like this. You take into account what is going on and understand what has happened in the first few steps then keep deriving to get the expression of what you need in terms of things that you have.

The first few steps usually require the most thinking of the situation and all the forces involved.

But yeah any way, this was from a uni worksheet. When I saw the question it took 2 minutes to solve, but its definitely within HSC standards and really tests your understanding of forces involving electrical and mechanical components.

 

[astroman]

Re: HSC Physics Marathon 2014

Good Luck

 

[duhdevitt]

HSC Physics Marathon 2015

or 2014 #yoloswagdw

bit late but why not do another marathon again cos why not
(copy and pasted from last year's cos ceebs)


The HSC Physics Marathon is an open chain of questions between students. It works by answering a question then posting another question and allowing the cycle to repeat itself.

Rules
- After answering a question, always provide a new one - this is what keeps the thread alive.
- Allocate a number of marks for any question that you post.
- Do not cheat, if you cannot answer a question, do not search how to answer the question but rather, allow other students to answer the question..

Tips
- It may help to write your answers on paper before typing them on this thread as it will mirror your exam.
- You may post more than one question.
- When possible, after questions have been answered, you can peer mark using the marking scheme.

 

[duhdevitt]

re: HSC Physics Marathon Archive

question 1
yolo

 

[astroman]

re: HSC Physics Marathon Archive

excellent, was waiting for one of these Mods please sticky

 

[duhdevitt]

re: HSC Physics Marathon Archive

so I think you start answering aha

 

[astroman]

re: HSC Physics Marathon Archive

too busy soz, got math test tmmrw. will contribute later on

 

[duhdevitt]

re: HSC Physics Marathon Archive

all good, good luck

 

[anomalousdecay]

re: HSC Physics Marathon Archive

Good idea. I'll post some questions up in a timely manner mainly on the other two core modules (however, get the question already up there answered first!).