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.