2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34879The concept "centre of mass" is analyzed in spaces with torsion free flat linear connection. It is shown that under sufficiently general conditions it is almost uniquely defined, the corresponding arbitrariness in its definition being explicitly described.15 LaTeX pages. For related papers, visit the "publication" pages at http://theo.inrne.bas.bg/~bozho/General Relativity and Quantum CosmologyMathematical Physicstext