Jump to content


Welcome to BrainDen.com - Brain Teasers Forum

Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account.
As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends.

Of course, you can also enjoy our collection of amazing optical illusions and cool math games.

If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top.
If you have a website, we would appreciate a little link to BrainDen.

Thanks and enjoy the Den :-)
Guest Message by DevFuse
 

Photo
- - - - -

Magnet


  • This topic is locked This topic is locked
103 replies to this topic

#31 Slick_Rick9009

Slick_Rick9009

    Junior Member

  • Members
  • PipPip
  • 20 posts

Posted 26 July 2007 - 06:25 AM


It's even easier than all that filing and breaking and stuff... Pick up one and try to pick up the other. The one that will pick up the other is the magnet.



stick one rod to the other



What??!!?!?

So the two rods attract, yes, we know one is a magnet. The magnetic attraction between the rods is a function only of the distance between them and the power of the magnetic field. Holding the magnet will not increase it's energy flow and reveal it. If the magnet is strong enough to lift the rod off the table, it will also be strong enough to lift itself off the table when passing the rod over it!




I looked at the top post and thought the exact same thing. But after thinking I realized that if you try to pick up the one laying on the ground by the center then only the magnet with be able to if it's poles are at the ends. To make sure they are then you could simply hold one of the bars by it's very end with just two fingers very gently and move it along the other one without letting them touch. If the bar pulls toward the end then that's where the poles are. If it doesn't pull anywhere, switch bars. This could also be used as another solution in itself. Because, if you are holding the magnet then it will pull just as strongly no matter where it is in relation to the bar leying on the ground. If you are holding the non-magnet then it will pull more strongly when you are over the poles. Please correct me if I am wrong. But I am pretty sure this would work.
  • 0

#32 Slick_Rick9009

Slick_Rick9009

    Junior Member

  • Members
  • PipPip
  • 20 posts

Posted 26 July 2007 - 06:29 AM

Also, to notalot, those answers weren't by the admin, those were the provided solutions when this puzzle was published. I could be wrong but I don't think he created this puzzle or those answers. (Note, that isn't sarcastic.)
  • 0

#33 Garrek99

Garrek99

    Junior Member

  • Members
  • PipPip
  • 60 posts

Posted 27 July 2007 - 12:59 AM

That's not what the host was trying to say.

Suppose that this is your magnetized rod:

II
II
II
II

The poles can be towards the top and bottom and also the poles can be left to right.
So, imagine that all the "I"s on the left are negatively charged and all the "I"s on the right are positively charged. That would be a magnet whose poles run through its entire length.
  • 0

#34 Mugsi

Mugsi

    Newbie

  • Members
  • Pip
  • 5 posts

Posted 19 August 2007 - 01:41 AM

Magnet - Back to the Logic Puzzles
This is a logic puzzle published in Martin Gardner's column in the Scientific American.
You are in a room where there are no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify this magnet?


Spoiler for Solution



Oh, i was watching an episode of Brainiac, and if you had some cereal, you could pour some milk into a bowl, (or any liquid) and then put one bit of cereal floating on the milk, then get the 2 rods, and hover them over the bit of cereal, whichever the bit of cereal responds to the rod that is the magnet, I probably phrased that badly, but you know what I mean. and it's because cereal has iron in it
  • 0

#35 Argetlam42

Argetlam42

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 24 August 2007 - 06:03 AM

For iron to act as a magnet, it has to be electrified. So if you touch one and get zapped, that's the magnet.
  • 0

#36 rubik

rubik

    Newbie

  • Members
  • Pip
  • 5 posts

Posted 05 September 2007 - 01:20 AM

If cereal has IRON in it, then it has METAL in it. So, you can't use it.

Then, humans have iron in them too (hemoglobin), so we can't be in the room either... so, NOW how do we figure this one out?!!?

Unless certain forms of metals don't count, like oxides (rust in this case) or complex molecules which happen to contain the atomic forms of transition metals (look up a periodic table)...

Since alot of puzzles on this site become debunked due to technicalities, then I hearby declare this one unsolvable, since humans contain iron. And the last time I checked, iron was a metal.

Done.
  • 0

#37 JohnSantaFe

JohnSantaFe

    Newbie

  • Members
  • Pip
  • 5 posts

Posted 07 September 2007 - 06:10 PM

Haven't seen this answer yet;

Rub your hands really fast over your hair to build up a charge. Hold the ends of each rod up to your hair. One of the ends should repel the hair. That's the magnet.

(This assumes humans are allowed and the human is not)
  • 0

#38 Gwailo

Gwailo

    Newbie

  • Members
  • Pip
  • 2 posts

Posted 25 September 2007 - 01:38 PM

place one rod on the ground (horizontal) and hold the other a short distance away from it in a vertical position like this I _
if the rod on the ground spins (to line up with the rod you are holding) as you move the vertical rod then the rod on the ground is the magnet. If it does not spin then the rod you are holding is the magnet.

Try it with two nails and see.
  • 0

#39 rjevans

rjevans

    Newbie

  • Members
  • Pip
  • 2 posts

Posted 25 September 2007 - 02:45 PM

wouldnt both of them be magnetic since they are made out of iron lol wouldnt it
  • 0

#40 Pinrelina

Pinrelina

    Newbie

  • Members
  • Pip
  • 1 posts

Posted 07 October 2007 - 07:08 PM

Put one rod flat on the floor and spin it on its axis two or tree times. If it always stops pointing to the same direction, its a magnet (always points to the north pole). So the other is an iron. But if it points to random directions, its not a magnet, so the oter rod is.
  • 0




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users