What relationships should be formed here?

peglegmeg152

I am currently doing a senior physics experiment where we are stopping a computer fan (with steel glued on to the blades) with an electromagnet, and measuring the time it takes to stop at varied resistances (using a rheostat).

I also need to calculate the angular and linear momentum and torque (and possibly other things). I am confused about what relationship should form between the time the fan takes to stop and the resistance - as well as how to go about collecting enough data to calculate the other things (momentum etc.)

Any help/advice/suggestions would be MUCH APPRECIATED!

Thanks in advance.