Question. (2 Viewers)

[hit patel]

A magnet was dropped through a plastic tube and the magnet dropped into the hand at t=1.3s. The magnet was then dropped into an equal diameter aluminium tube and then the magnet dropped at t=2.4 s.
Part a) already explained

Now when the tube was sliced straight down through the middle and the magnet was dropped again, Explain qualitatively What would be observed and also explain why?


Note: This corresponds to faradays law of induction , back emf and lenz law but i cannot comprehend what would happen and why and how slicing the tube affects it.

 

[Menomaths]

The magnet would fall through unimpeded as no eddy currents will be produced which resist the change in motion since the eddy current loops cannot be completed?

 

[iBibah]

The magnet would fall through unimpeded as no eddy currents will be produced which resist the change in motion since the eddy current loops cannot be completed?

Won't there still be eddy currents, they're just smaller though?

 

[Menomaths]

Won't there still be eddy currents, they're just smaller though?

No idea, lets wait for someone to clarify

 

[iBibah]

No idea, lets wait for someone to clarify

lol it was a question to make you think.

The eddy currents are in fact reduced, however in terms of the hsc, we are meant to say they're so small they're negligible.

 

[Menomaths]

lol it was a question to make you think.

The eddy currents are in fact reduced, however in terms of the hsc, we are meant to say they're so small they're negligible.

Can I say what I said or do I have to say the lengthy explanation they're so small they're negligible?

 

[iBibah]

Can I say what I said or do I have to say the lengthy explanation they're so small they're negligible?

I think it would be better to say they're negligible rather than they don't exist.

 

[Menomaths]

Alright, thanks. Does this answer your question Patel?

 

[hit patel]

Alright, thanks. Does this answer your question Patel?

Yes thank you Menomaths, Ibibah. So the magnet would just fall through with a close time to that when the magnet falls through plastic tube. Therefore the explanation is that the eddy currents produced are minimal allowing the magnet to retain its kinetic energy?

 

[Squar3root]

Won't there still be eddy currents, they're just smaller though?

Yes they exist, but are much smaller as the eddy current cant form a hug loop instead like 10's of smaller ones which has negligible efffects compared to the one that has no split in it

 

[Fizzy_Cyst]

HSC wants you to say that due to the slit, eddy currents will be minimised and no force due to the eddy currents will be experienced by the falling magnet, so it will pass out of the tube in the same amount of time as the plastic tube.

Have a look at 2011 HSC Q25 and the associated marking guidelines / notes from marking centre.

This is of course, wrong.. But, hey.. That's HSC Physics!

 

[someth1ng]

HSC wants you to say that due to the slit, eddy currents will be minimised and no force due to the eddy currents will be experienced by the falling magnet, so it will pass out of the tube in the same amount of time as the plastic tube.

Have a look at 2011 HSC Q25 and the associated marking guidelines / notes from marking centre.

This is of course, wrong.. But, hey.. That's HSC Physics!

This is correct.

 

[Randox]

HSC wants you to say that due to the slit, eddy currents will be minimised and no force due to the eddy currents will be experienced by the falling magnet, so it will pass out of the tube in the same amount of time as the plastic tube.

Have a look at 2011 HSC Q25 and the associated marking guidelines / notes from marking centre.

This is of course, wrong.. But, hey.. That's HSC Physics!

Lol

 

[Fizzy_Cyst]

What really happens..

http://www.hscphysics.edu.au/resource/MagnetRace.flv

 

[hit patel]

What really happens..

http://www.hscphysics.edu.au/resource/MagnetRace.flv

Thanks