Compute all parts of given questions:
Question I: Vector A has a negative x component 3 units in length and a positive y component of 2 units in length.
Part A: Determine an expression for vector A in unit vector notation?
Part B: Determine the magnitude and direction of A.
Question II: What vector B when added to A will give a resultant vector with no x component and negative y component 4.0 units in length?
Write your solution in appropriate format and provide references.