Is it possible to make particles inherit the velocity of geometry that is emitting the particles and that is being animated along a curve (using Animation tab-Follow Path)?

If I connect a Trail node to the object node to calculate the velocity of the object this works in other cases when not using Follow Path, e.g. keyframed animation.

Object merge the object into a new object with “into this object” as transform. The calculate v and use that as the emitter.

OK I think I worked it out, thanks. Does this seem right?

You create a Geometry node, delete the file node inside and add an Object Merge node, then select the other node (e.g. the sphere you used to emit particles from) for its Object1 field and set Transform: Into this Object.

Then connect a Trail node to the object merge node (at obj level) and set its parameter to Result Type: Compute Velocity.

Then in the AutoDopNetwork select the object_source node and set the geometry node for its Source tab-SOP field. In Attributes tab set Initial Velocity: Use inherited velocity.