The linear velocity vector of this BasePart|part’s assembly. It’s the rate of change in position of the assembly’s BasePart/AssemblyCenterOfMass|center of mass in studs per second.

If you want to know the velocity at a point other than the assembly’s center of mass, use BasePart/GetVelocityAtPosition.

Setting the velocity directly may lead to unrealistic motion. Using a VectorForce constraint is preferred, or use BasePart/ApplyImpulse if you want instantaneous change in velocity.