2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84286A good candidate to the role of passive gravitational mass of a Schwarzschild's incompressible sphere is represented by the substantielle Masse of the sphere, which is larger than the active gravitational mass. Presumably this inequality has a general validity, i.e. it is not limited to the homogeneous spheres of incompressible fluids.6 pages, PDFGeneral Physicstext