Awatmath.1334 net.general utzoo!decvax!watmath!kpmartin Fri Dec 18 21:56:37 1981 unbalanced fan Actually, since objects which are rotating tend to rotate about their centre of mass, it seems to me that the lightest blade (hence the one farthest from the centre of mass) would be the one which sticks out. Consider the point on the line connecting the fan's CM and the motor's CM which divides this line in the ratio of the two masses. This is the CM of the entire assembly, and will remain fixed in space. The two objects will wobble in such a way that their centres of mass (masses?) will "orbit" about the combined centre of mass. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.