I'm trying to estimate the magnetic force which develops on a truss-like ferromagnetic structure (I want to estimate the motion of the object) in a uniform magnetic field, and I came to realize that I have a fundamental gap in my knowledge.
My question is: how do I calculate the magnetic force in a uniform magnetic field with magnitude $B$, related to a rod-like object with length $L$, diameter $d$, and mass $m$?
From what I could fathom so far, the force should be independent of the mass. It is mainly depended on the intensity of the field.
An initial guess is that the force should be independent of the mass. However, that cannot hold because then what happens if I take two masses and glue them together?