Force between two magnets as related to distance

[Magnet4less]

Hello,
I am new to the forum, thus please be patient with me.

I have a little bit of a problem...

Currently working with magnets. Basically, I need to derive an equation for the attractive/repulsive force between two magnets given a distance between them. The most important thing is that these magnets not interfere with each other, in other words I need the attractive/repulsive force to be zero.

Thoughts so far...
- Newton's Universal Gravity equation
- F = GMm/R²
- manipulate the pull force of the magnet to derive a mass...divide pull force of magnet by 9.8m/s^2
- need to set F to an infinitely small amount and solve for R

I do not get offended very easily, so if you need to completely slam my thoughts so far in order to get me on the right track, I understand.

Thank you in advance for your help

 

[tiny-tim]

Welcome to PF!

Basically, I need to derive an equation for the attractive/repulsive force between two magnets given a distance between them.
The most important thing is that these magnets not interfere with each other, in other words I need the attractive/repulsive force to be zero.

Hi Magnet4less ! Welcome to PF!

I'm not sure what you mean … do you mean you want the gravitational attraction between the magnets to be balanced by their magnetic repulsion?

(but if so, why are you using the value of g here on Earth?)

 

[Magnet4less]

I'm trying to figure out how close I can place the magnets to one another without them visibly affecting each other.

 

[tiny-tim]

Hi Magnet4less!

The exact formula for the force between two bar magnets is in wikipedia:

http://en.wikipedia.org/wiki/Magnet#Force_between_two_bar_magnets ​