HSC Physics Marathon 2013-2015 Archive (1 Viewer)

[esaitchkay]

Re: HSC Physics Marathon 2014

Answers for the sniper question are 0.59º and 89º45'



I will give you a hint: It ends up as a quadratic in Tan.

If u want the worked answer, I will post up

I saw that identity but didn't use it before... LOL all good, thanks

 

[Fizzy_Cyst]

Re: HSC Physics Marathon 2014

How we going?!?!

Time to revive this thread me reckons!

'Discuss the effect that devices utilising the motor effect have had on society'

COME @ ME

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

The legend returns XD

Btw, you can use the questions I post up Fizzy for your classes and the what not (I give you permission).

 

[Fizzy_Cyst]

Re: HSC Physics Marathon 2014

The legend returns XD

Btw, you can use the questions I post up Fizzy for your classes and the what not (I give you permission).

Thanks mate

 

[Fizzy_Cyst]

Re: HSC Physics Marathon 2014

BUMP!

5 months, NO ANSWERS! CMON PPLS!

How we going?!?!

Time to revive this thread me reckons!

'Discuss the effect that devices utilising the motor effect have had on society' (5 marks)

COME @ ME

 

[Fade1233]

Re: HSC Physics Marathon 2014

BUMP!

5 months, NO ANSWERS! CMON PPLS!

 

[QZP]

Re: HSC Physics Marathon 2014

View attachment 30911

read the q pls

 

[Fade1233]

Re: HSC Physics Marathon 2014

read the q pls

Devices using motor effect and effect on society ? Yeh what did I do wrong?

 

[iStudent]

Re: HSC Physics Marathon 2014

Devices using motor effect and effect on society ? Yeh what did I do wrong?

You talked a lot about how the devices work. Not so much on their specific effects on society.

 

[Fade1233]

Re: HSC Physics Marathon 2014

You talked a lot about how the devices work. Not so much on their specific effects on society.

Its a 5 mark question. I had to include that- cos if they didnt mention which device then atleast 1 mark for identification, 2 marks for explanation, 2 marks for effects on society or 1 for evaluation.

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

1+2+2+1 != 5

 

[iStudent]

Re: HSC Physics Marathon 2014

Its a 5 mark question. I had to include that- cos if they didnt mention which device then atleast 1 mark for identification, 2 marks for explanation, 2 marks for effects on society and 1 for evaluation.

What I think is that 1 maybe 2 marks for identification + explain how it uses motor effect (brief). 3 maybe 4 marks for discussing positive and negative effects on society . (it doesnt ask for an evaluation). I don't think you need to go into the detail you went into to describe how they work. Probably a briefl outline of where the motor effect comes into play would suffice. (what I think anyways, because the question doesn't ask for how they work)

 

[Fade1233]

Re: HSC Physics Marathon 2014

What I think is that 1 maybe 2 marks for identification + explain how it uses motor effect (brief). 3 maybe 4 marks for discussing positive and negative effects on society . (it doesnt ask for an evaluation). I don't think you need to go into the detail you went into to describe how they work. Probably a briefl outline of where the motor effect comes into play would suffice. (what I think anyways, because the question doesn't ask for how they work)

Yeh because whenever I see past papers thats how the structure it for 5 markers. Or maybe 2 for explanation, 3 for society. Because I thought in Discuss you had to put evaluation.

1+2+2+1 != 5

I meant to say 'or evaluation (1)'

 

[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).
(answer: 0.5 m/s)

 

[iStudent]

Re: HSC Physics Marathon 2014

Yeh because whenever I see past papers thats how the structure it for 5 markers. Or maybe 2 for explanation, 3 for society. Because I thought in Discuss you had to put evaluation.


I meant to say 'or evaluation (1)'

No evaluations in discuss questions I believe. only in assess or evaluate questions

 

[Fade1233]

Re: HSC Physics Marathon 2014

v= 2 BIL/(tm) ?

m=mass L= length of conductor t= time B= mag field strength I= current

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

v= 2 BIL/(tm) ?

m=mass L= length of conductor t= time B= mag field strength I= current

Slightly off there.

I think you have the right idea, but you messed up somewhere. This is where it would be good to see your working to check what you forgot to do and I could give you a hint.

 

[Fade1233]

Re: HSC Physics Marathon 2014

Haha sorry, I dont know what I did wrong? any hints?
Work done to t seconds= KE possessed at t seconds=Fd=nbild=(1/2)(mv^2)
But v=d/t Therefore BILv/t=(1/2)(mv^2)
Therefore v=2BIl/tm.
Any hints?

 

[anomalousdecay]

Re: HSC Physics Marathon 2014

Haha sorry, I dont know what I did wrong? any hints?
Work done to t seconds= KE possessed at t seconds=Fd=nbild=(1/2)(mv^2)
But v=d/t Therefore BILv/t=(1/2)(mv^2)
Therefore v=2BIl/tm.
Any hints?

You related torque to energy here. The wire does not rotate so there is no torque acting on it.....

Also, we can't say that work done here is equal to the force applied over a distance, because the work applied is by VIt in the conductor and the magnetic field, which does not lead us to any useful information to find the speed of the wire.

 

[Fade1233]

Re: HSC Physics Marathon 2014

You related torque to energy here. The wire does not rotate so there is no torque acting on it.....

Also, we can't say that work done here is equal to the force applied over a distance, because the work applied is by VIt in the conductor and the magnetic field, which does not lead us to any useful information to find the speed of the wire.

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?