What is rigid body?
Let $\mathop A\limits^ \to $ be a unit vector along the axis of rotation of a purely rotating body and $\mathop B\limits^ \to $ be a unit vector along the velocity of a particle $ P$ of the body away from the axis. The value of $\mathop A\limits^ \to .\mathop B\limits^ \to $ is
How can general body be obtained ?
Characteristic of rotational motion.
How many degrees of freedom does a rotational motion about fixed axis ?
Which forces needed for the rotational motion about a fixed axis ?