Linear Velocity

A LinearVelocity constraint applies force on an assembly to maintain a constant velocity. It can be set to apply force along a Vector3, line, or 2D plane.

Relativity

Application of velocity can be controlled through the constraint's RelativeTo property. If set to World, force will be applied in world coordinates, independent of the parent or attachment orientations. If set to Attachment0 or Attachment1, force will be applied relative to Attachment0 or Attachment1 respectively.

RelativeTo = World
RelativeTo = Attachment0