Force on magnet in magnetic field

[Teppei]

Hello,
i've recently found the post
"How to calculate the force acting on a magnet placed in a magnetic field?"
at
http://physics.stackexchange.com/qu...acting-on-a-magnet-placed-in-a-magnetic-field

in another Forum
and the answer said smth about an interaction energy.
how can i get this formula? i can't really understand.

Regards

 

[Simon Bridge]

They work out the force from the potential energy function.

 

[Teppei]

so i just have to take the potential energiy fuction, and get the volume integral for the interaction and so the force?

 

[Teppei]

then for calculating i fill in the formulas ? and well, is B the allover flux density?

 

[Simon Bridge]

The force is usually the gradient of the potential energy function ... the integral was to find the function... so yeah, basically. It looks odd because magnets are annoying.
The formula does not cover torques... you will have to take account of the freedoms in the physical system you are concerned with as well.

 

[Teppei]

How can i get the torque in? and, well, does it apply for magnets in the magnetic field of a solenoid? (inside)