5.6. Moment of impulse of the material point and solid

Radius-vector product material point on its momentum: called the angular momentum , this point relative to the point O (Fig.5.4)

. Vector sometimes also called the moment of momentum of a material point. It is directed along the axis of rotation perpendicular to the plane drawn through the vectors and and forms with them the right three of vectors (when observed from the top of the vector, it can be seen that the rotation is the shortest distance from to going counterclockwise).

Vector sum of impulses All material points of the system are called angular momentum (momentum) systems relative to point O:

Vectors and mutually perpendicular and lie in the plane perpendicular to the axis of rotation of the body. therefore . Taking into account the relationship of linear and angular values

and directed along the axis of rotation of the body in the same direction as the vector .

In this way.

The moment of the impulse of the body relative to the axis of rotation

those.

(5.9)

Consequently, the angular momentum of the body relative to the axis of rotation is equal to the product of the moment of inertia of the body relative to the same axis and the angular velocity of rotation of the body around this axis.