PHYSICS 135 Lecture Notes - Lecture 3: Unit Vector, Unit Circle
Document Summary
A unit vector is a vector with a unit of 1: think unit circle from trigonometry. Denoted by a ^ over the top or a-hat . Usually layered over another vector: always points in the direction of the original vector. Your total velocity is a sum of vector components: ex: you walk through a train as it moves over the track. Your relative velocity can be determined using vector components describing your direction and speed. V-arrowperson-groud = v-arrowperson-train + v-arrowtrain-ground: ex: dog swims directly across a river at 1. 2m/s while the river current pushes him to the right at 1. 2m/s. V-arrowdog-shore=v-arrowdog-water + v-arrowwater-shore: ex: the same dog is swimming, but this time, he is attempting to end up directly across the river from where he started. Water: flows west at 1m/s relative to the shore. Scalar product: multiply two vectors to get a scalar quantity, also known as the dot product, r f = f(r cos( )) = fr.
