Vibrations of the Mass Variable Systems
27
Fig. 1 Model of body separation
intervals: dynamics of the initial body, dynamics of discontinual mass separation and
dynamics of the separating body and of the remaining body.
To describe the dynamics of the system, the principle of linear momentum and
the principle of angular momentum are applied.
2.1 Principle of Linear Momentum
For the initial body with mass M and velocity of mass center v S , the linear momentum
is
K = Mv S
(1)
If the separated mass is m and the velocity of mass center is v S2 , the linear
momentum is
K 2 = mv S2
(2)
The linear momentum of the remaining mass is
K 1 = (M − m)v S1
(3)
where v S1 is the unknown velocity of the mass center S 1 .