Perpendicular

Hello
I want to move a circle onto a curve, in such a way, that it lays perpendicular to that curve. Is there a command which can rotate things so that they lay perpendicular to the tangent of a certain point of a curve?

is this what you re after ?
move green circle towards black curve ?

construct a offset curve (red):
_offset
(nested command:) _radius (meassure the radius as offset distance)

then move / copy with object snaps. for example
_CenterSnap
_NearSnap
if the direction is given you can use additional construction line or modelling aids.

hope this helps - kind regards -tom