Fig. 401.01 Four Vectors of Restraint Define Minimum System:
Investigation of the requirements for a minimum system.
A. One vector of restraint allows ball to define complete sphere__ a three-dimensional system.
B. Two vectors: a plane__ a two-dimensional system.
C. Three vectors: a line__ a one-dimensional system.
D. Four vectors: a point__ no displacement.
E. Note the possibility of turbining with the position otherwise fixed by the four vectors of restraint.
F. The four vectors define the tetrahedron: the first identifiable “system” __ a primary or minimum subdivision of Universe. The ball lies at the center of gravity within the tetrahedron.