If two discs of equal mass and volume are parallel to each other but not touching, share an axle but using magnetics do not touch it, are not under gravity, and begin to rotate in opposite directions to each other...Assuming the discs are both parallel to the y axis and the axle is along the z axis, does the entire object (discs and axle) begin to also rotate on the x axis?
This isn't a school question - just something I've been wondering about. Something makes me think I've seen a similar situation result in rotation starting on the x axis, but I can't find anything stating as much. Sorry I have no diagrams. Like I said, just a curiosity.
As a followup to Gert's response: Does the answer about what would experience the torque depend solely on what part or parts of the discs the increase in angular speed were applied to or originated in? Or is it simply that any increase, regardless of origin, would start to cause the rotation.?