5.7. The basic equation of the dynamics of rotational motion

According to equation (5.8), Newton's second law for rotational motion

By definition, angular acceleration and then this equation can be

rewrite as follows

in view of (5.9)

or

(5.10)

This expression is called the basic equation of the dynamics of rotational motion and is formulated as follows: the change in the angular momentum of a rigid body equal to moment momentum all external forces acting on this body.