4. An orthodontist wants to apply a force of 1 N to the root of the tooth shown in (b). In order to IN do so the orthodontist applies a force at a bracket attached to the crown of the tooth as shown in Distance (a). What else does the orthodontist need to = 10 mm apply to the bracket or accessible part (non-grey IN area) of the tooth so that the force system in (a) is statically equivalent to that in (b)? Be specific in your answer and add the necessary changes to Figure (a) and indicate directions and magnitudes of all required vectors to make (a) show an equivalent force system to (b). (a] (b)