https://reference.wolfram.com/system-modeler/libraries/Modelica/Modelica.Mechanics.MultiBody.Examples.Elementary.PointGravityWithPointMasses.html
Modelica: Mechanics.MultiBody.Examples.Elementary.PointGravityWithPointMasses - System Modeler...
Two point masses in a point gravity field (rotation of bodies is neglected)
modelicamechanicsmultibodyexampleselementary