  Influence of noncommutativity on the motion of composite system is studied in
noncommutative phase space of canonical type. A system composed by $N$ free
particles is examined. We show that because of momentum noncommutativity free
particles of different masses with the same velocities at the initial moment of
time do not move together. The trajectory and the velocity of free particle in
noncommutative phase space depend on its mass. So, a system of the free
particles flies away. Also, it is shown that the total momentum defined in the
traditional way is not integral of motion in a space with noncommutativity of
coordinates and noncommutativity of momenta. We find that in the case when
parameters of noncommutativity corresponding to a particle are determined by
its mass the trajectory and velocity of free particle are independent of the
mass, also the total momenta as integrals of motion can be introduced in
noncommutative phase space.
