Magnetized Rods: CR4 Challenge (12/15/09)

Havn't we had this Q before?
I won't spoil it for anyone else by giving the A
Del

Yes! But the real question is; has the answer changed?

By making a compass the one that is magnetized would turn pointing to the poles in the same direction every time.

My thoughts exactly. Rated a GA for getting there first.

Cheers,

Pete.

Great answer, Dac I was thinking the exact same thing. True logic reigns supreme!!

Me too.

y be naked??

"y be naked??"

exactly. this is one of the conditions of the problem that needs to be explained. all answers presented above is unrelated to this.

or is "naked" just a figure of speech?

The main reason is that it's always more fun to do this kind of thing naked. The second reason is that it is pretty easy to make a compass out of a bar magnet and some thread torn from your clothes (just hang the bar from a thread).

It is (or so I have heard) much harder to make a compass using some part of your body as the fulcrum.

"it's always more fun to do this kind of thing naked"

<LOL>

however, methinks you just introduced another degree of difficulty to the problem.

"some thread torn from your clothes"

they put you in the jail without your clothes!

but really, it is quite easy to determine which of the rods is magnetic just by feel. just can't make anything out of why you have to be naked to do this.

Those who still have hair don't need a thread to make a compass, or are the prisoners shaved as well?

I too thought of touching one rod end to centre of other one. But I am not the first.

some thread torn from your clothes : I pull one of my hair and use it as a thread and make a compass! (But for this also, i need not be naked)

Come on guys! It's simple. A fully dressed person could simply touch the bars to their belt buckle or ear rings or whatever other metal snaps etc. might be on their clothes. By stating that you are locked naked simply removes these avenues of testing which makes the problem more difficult. I have spoken. The Digital Man

so maybe the problem should've been reworded to say: "using only the 2 rods in your hands, and unaided by any other object or material, such as metallic objects in clothing, or the jail bars, or iron filings, etc., determine which rod is magnetic, and which is not."

the whole thing about nakedness was just to throw you off....???

Look, if you have the resources and audacity to kidnap someone, lock them in a padded cell and then screw with their mind by telling them they won't be released until they pick which is the magnetised one of two otherwise identical rods, then you may as well go all the way and make them do it naked. It's just common sense.

Why not be naked?

So that the effect of the magnetised rod near my iron hip joint will be more sensitively felt. (Although I suppose I could have done this with my hat on)

If I can break each of the two rods into halves and then observe the attraction / repulsion or no effect of the related broken halves on each other, I guess I should be able to see the sunshine and breathe the fresh air.

I place one bar horizontally on another bar exactly at the center point to balance. If the top bar does not rotate horizontally, it is non-magnetic. To confirm, I interchange the position of upper and lower bars to see that the upper bar rotates horizontally towards the geo. N & S poles.

If you place rod (a) at right angles to rod (b) and exactly half way along its length it will attract the rod to it if it is the magnitised one. If it is not it will try to move to either end of the other rod.

Take one rod and apply the end to the middle of the other rod. If there is attraction, you're holding the magnetised rod. If not, you're holding the unmagnetised rod.

Cheers.......Codey

I'll give you a GA for that, but I'll be damnned if I ever want to be your cell-mate.

I laughed so hard I had to give a GA. Thanks for waking me up.

There is only one problem, and that is in the end.

When you stand on one leg, on the bar of soap- _{it is slippery isn't it, in the bath?} You are most likely to fall down, and as per Murphy's law, on your butt,

Then what happens to the carefully positioned magnet?

I like the #32 better- where magneto therapy is used. In fact I have heard of some cures where the magnetised water is used for curing all and any illness (H1N1 and HIV excluded). So treat yourself with the water for sufficient time, if you are cured, that is the magnet. If you aren't, it does not matter.

The best is #31 - hold them in yoyr hand. The one pulls is the magnet, the one pulls is the iron rod.

Why not make electricity in the rod with rotating magnet and light a bulb? rotating Iron can not do it.

Beautiful Andy.

The whole exercise is just an exercise in futility.

The answer is simple. The rod with magnetic properities will immediately jump to the cast iron fillings in my teeth. Problem solved.

Wow, Andy, you are have my kind of A$$ho!!e. Tell me, why does it feel so much better to pull the rods out than to put them in? Is this the voice of experience?

LOL

Never had your Prostate checked???

So what you are suggesting is that every prisoner that is released should be issued with a magnetized bar and pointed in the right direction. Rehabilitation at the highest level.

Regards JD.

I don't believe it, two GAs for using my rear end instead of my head!!!!

Many thanks Guys!!

I would take one of the iron rods and touch the other with it, noting the strength of the magnetic attraction. I would then with the rod I initially grasped, keeping one end upward strike it very hard the cell floor about 20 times (making a note which end I was striking with). I would then with the my "striked" rod, touch the other rod on both ends making a note any change in magnetic force. If it repelled the other rod when touching either end, I would know that the other rod was the one that was initially magnetized. If the magnetism increased or decreased I would know that the "striked" rod was the initially magnetized rod. This method works because the striking force in one direction tends to allign the molecules in a single direction thus creating magnetic poles (north and south) like poles repel, unlike poles attract.

suspend both bars at the midpoint. the bar that aligns itself in a north-south direction is magnetized. So now, unlock the cell, I have things more important to do.

If you have no clothing then I'm assuming you have no watch, i.e. metal with which to assist with the experiment, therefore you can only use the rods to answer the question. One rod is a magnetized iron rod and the other rod is simply an iron rod. Take one rod (Rod A) and while holding it at one end slowly run the end of Rod A down rod B from one end to the other and see if there is a "pull", i.e. the magnetic pull. Then switch rods. Whichever rod is pulled towards the other rod is simply the iron rod; the rod doing the 'pulling' is the magnet.

I would use the metal plate in my head, but if I were not in a hurry, I would first develop arthritis in similar joints, such as my wrists or ankles, then hold the rods to my joints. The one that hurts less and is cured fastest is the one that is exposed to magnetism. Would I be provided with water during my incarceration? If so, I would break the rods into length that would fit on the surface of the cup and gently place the rod fragment on the surface tension. One of the rods would orientate itself north and south no matter how I oriented the cup. The other would just sit there. Because of my breakage I now have several smaller magnets, which I could offer to my jailor in exchange for my freedom.

Hold the rods perpendicular,then move the end of one along the length of the other. The rod that is magnietized will have North and South poles, one at each end, and in the center will have NO magnetic force. If the moving rod has uniform attraction to the static one, it is magnetized, and one pole is attracting the non-magnetized static rod.

If, on the other hand, the magnetic attraction varies , decreasing as the moving rod nears the center of the static one, then the static one is magnetized.

One other way. Not as practical, but I think it would still work. Slap one rod on a surface several times, enough to displace the fixed magnetism of the metal. If the rod you've been slapping has a reduced or no magnetic effect on the other rod, then it was the magnet.

Depending on where you've been keeping the rod as in the previous scenarios, you may be busy slapping another rod.

"No, you pick up the soap!"

Crap! BOBCO came up with this one before me. My apologies, the soap is yours.

Stand one rod on its end on the floor. Balance the other rod at its midpoint on top and if it rotates to point N S you know it is the magnet etc.

Why over complicate it? All you have to do is lay one on the floor and bring one end of the other one very close to the exact center of the one on the floor. If they are attracted to each other then the one in your hand is the magnetised one. If not reverse positions and see if the one in your hand atracts the middle of the other one. Once you find the one that sticks to the middle of the other one, that is your magnetised one. It's not rocket science.

I would carefully balance one rod on the non-metallic bars and place the other rod as far away as possible to reduce the magnetic attraction between the rods. If the rod on the non-magnetic bars align itself North and South, then this is the magnetized rod. If not, I would exchange rods and repeat the procedure. The magnetized rod will attempt to align itself in the North/South direction.

"...you will be released when you can correctly identify which rod is magnetized and which is not."

Pick a rod at random. Tell the jailer that you think it is the magnetised one. If you are set free, then it was magnetised. If you are not, then you know the other rod is the magnetised one. Since you can now identify which bar is magnetic you will be released.

You make a string from your hair and tie it in the middle of a bar. Mark one end of the bar by spiting or some other means. one bar will point to magnetic north. Alternately for the bald professor, balance the bar on your fingernail if possible or the end of the other bar.(excreate something slippery if nessecary) what if gravity was caused by superspeed particals coming from all directions? How big would they be?

I therefore conclude, from the postulations above, that a poorly-worded problem statement results in ambiguity, and elicits answers that are poorly-worded and ambiguous.

Well, since that one went so fast, how about a twist? Suppose you had a mobius strip of iron that had been well annealed so it was isotropic after joining. Could you magnetize it so that one side is a north pole and one side a south pole?

Take a hair from your body, tie it around the centre of a rod, etc. if your hair is short you might wait for it to grow or tie several hairs together.

Bite yourself, dry the blood, grind it to fine powder, since blood contains iron it should cling a little to the magnetised rod.

Bite me!!

Bite him.

I assume this is a room on Earth. Balance each rod on your finger separately and away from one another (to prevent magnetizing the one not yet magnetized) and observe if one or the other seems to act as a compass to track magnetic north. You would need to probably run a few tests with different starting orientations possibly using the one not being tested as the "mark" where the tested bar points to. The one that consistently turns to track in the same orientation is the magnetized one.

Except a few posts and AG to be specific, nobody has concentrated on the most important information.

Why naked? What the hell one wants to do with three rods? one ferrimagnetic, one ferromagnetic and one paramagnetic?

what one should do is hang each rod marked in any direction. if the rod is magnetic it will align in the direction of the magnetic north. and this will give exactly get me out. it should be proved over and over changing the direction.

statistically every second answer will be correct!

So i have two tries to find out which box is magnetized; first answer is box A, if it is not correct the second Box (B) has to be it!