Displacement As A Vector:

Whenever displacement is defined in a straight line, it is a vector quantity since it has both magnitude (expressed in meters, kilometers, or another distance unit) and direction (that can be defined in different ways). Displacement magnitude is represented by a lowercase italicized letter; let's call it q. A displacement vector is represented by a lowercase boldface letter. In this conversation, let use q.

The displacement vector q_rm of Minneapolis associative to Rochester would be around 100 km in a northwesterly direction "as the crow flies." Since an azimuth bearing, it would be about 320 degrees, measured clockwise from true north. Though, if we speak about driving all along Route 52, we can no longer be able to define the displacement as a vector since the direction changes as the road bend, goes over hills, and dips into valleys. In this situation, we should denote displacement as a scalar, generally in lowercase italics. In this conversation let use q. We write q_rm ≈ 120 km.