Given a closed chain with a total length of 1.2m rotating at 1'800 rpm and a total mass of 0.4kg, what is the drag force pulling on one chain link?
I originally thought that since no link size was given I need to assume the link sizes to be infinitely small. Thanks to the answers below I now know this won't work. Yet I am still baffled as to how I could calculate the drag force without it, sure I could give a function of the drag force that is dependent on the link size, but looking at the parameters given I think I should be able to calculate the actual force.
Here is a video of a very similar experiment as we conducted and are asked to describe now: http://www.univie.ac.at/elearnphysik/video/PhysikI/rotKette_648x480.flv
I am glad for any hints and explanations.
Edit: Rewrote question to match exactly the problem description