# What is the retarding force due to eddy currents

I am currently struggling to find an expression to approximate the retarding force due to eddy currents when a magnet moves along at a speed $$v$$ beside a long, straight and flat conductive plate made of a metal that is not ferromagnetic.

It took a long time, but finally, I found this paper: https://deepblue.lib.umich.edu/bitstream/handle/2027.42/109373/me450w10project16_report.pdf?sequence=1

in which the force is approximated by the expression

This expression, however, applies to a rotating disk, rather than a plate. I tried modifying it so that it would apply to a plate, like this:

Would this be appropriate? I am quite new to torque and I don't fully understand it yet