Magnetic force between an unknown and known permanent magnet

[Sebastian_3835]

Dear helpers,
I working on an projekt for the University and for that I have to calculate forces between different magnets. The question that I have is: "Is there a way to calculate the force between two magnets if one is completely known and the other unkown. But you know the B-field of the unkown magnet on the surfacse of the known magnet".

Known magnet:
Shape: Cylinder magnet
Material: N50
Br=1425mT
Radius=22,5mm
High/Thickness=5mm
Distance to unknown magnet= unknown
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^B-Field = 4,2 mT and homogeneous

^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
___________________
| Blackbox |
|(unknown magnet) |
|___________________|
___________________
|__________________| Known magnet

^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
___________________
| Blackbox |
|(unknown magnet) |
|___________________|

I have found a formula that calculated approximately the forces between two completely same cylinder magnets in a defined distance.

https://en.wikipedia.org/wiki/Force_between_magnets

Where:
https://en.wikipedia.org/wiki/Magnetization

µ0 = 4π * 10^(−7) Hm ≈1,256*10^(-6) Hm
R=Radius
L=High/Thickness
x=Distance between the two magnets

When someon knows how this calculation is possible or maybe it's not possible I will be very thankful for this infromation :)

 

[Charles Link]

Suggestion for this is instead of computing the force between two magnets, have then placed at right angles to each other around a compass needle. (There will be a correction for the Earth's magnetic field). This would seem to be a better way to measure the magnetic field strength ## B ## and to compute the magnetization ## M ## than computing the mutual force between them. See also post 21 of https://www.physicsforums.com/threa...re-relationship-in-ferromagnets.923380/page-2 ## \\ ## Perhaps after a measurement like this to characterize them, you then might try to estimate the forces between them with some kind of calculation, and see how it agrees with experiment. Trying to work with the forces between them to compute ## M ## is a more formidable task, and you'd be better off already knowing what ## M ## is, and working from there. ## \\ ## ## \\ ## Edit: And I just noticed you deleted the homework template. In the future, please do not delete this template. Otherwise, you might see the moderators simply delete the post. One of the rules of the Homework section is the template must be filled out.