# Interesting Magnetix Set Question

1. Oct 18, 2004

### KrakaJap

I'm not very knowledgable of physics as my main focus is computer technology. However, I purchased a Magnetix set from a local store a few days ago because I remembered these kinds of sets when I was a kid. With this 20 peice set I created a hexagon and had one remaining ball left over. I wanted to see if this one ball would hold up the entire hexagon construction from the middle (knowing that the middle ball would be completely magnetized by it's surrounding 6 magnetic links. Of course this worked so I decided to set up a make-shift stand to hold this one ball and hang the hexagon construction from this one ball via magnetism only. Then I decided to spin this hexagon construction. (This is the child inside me of course) :) So I left this construction spinning while I went to eat dinner with my fiance. About 3 hours later it was still spinning with no sign of slowing down. So I decided to leave it until morning. Next morning it was still spinning! And at what seemed to be the same speed! 48 hours later It still seems to be spinning at the same speed. I always thought this was impossible outside of a vaccum. Can anyone explain this to me?

2. Oct 18, 2004

### Tide

The frictional force is VERY small! This is due to both the coefficient of friction being small and the condition that the normal force is small (the magnetic force is just slightly greater than the gravitational force.)

3. Oct 18, 2004

### KrakaJap

Interesting... but what about wind resistance? Shouldn't that slow it down considerably after a short time?

4. Oct 18, 2004

### Tide

Certainly air drag will slow them down but air drag varies as the square of the speed. The magnets are rather dense and are moving slowly enough that drag is not very effective at slowing them down though 48 hours does seem a long time!

5. Jun 6, 2009

### RMorewood

Has anyone attempted to reproduce this experiment? I attempted it and my hexagon only spins from several seconds, up to about 2 minutes. It often develops a large wobble as it slows down.