Couples Rotate Objects: Understanding Rotation Points

[chandran]

when a couple acts on an object it will tend to rotate it and it will not tend to translate it

But the sentence "tend to rotate" but tend to rotate about which point or axis?

 

[Astronuc]

How about the center of mass?

http://hyperphysics.phy-astr.gsu.edu/hbase/cm.html

See also - http://hyperphysics.phy-astr.gsu.edu/hbase/torcon.html

Couples have equal moment arms about some point or axis. What happens when that point or axis does not coincide with the center of gravity of a mass?