Physics 197 Lecture 2: Vectors

• School: WUSTL
• Department: Physics
• Course: Physics 197
• Professor: Ferrar

Document Summary

Scalar quantity: any quantity (such as speed) that we can completely describe using a single numerical value: energy, mass, time, electric charge, and temperature. Vector: a quantity (such as velocity) that has a direction in addition to a numerical magnitude: direction: the aspect of the vector that speci es its orientation in space, magnitude: the numerical value associated with a vector. Vector sum: a vector whose components are the sum of the corresponding components of the vectors being summed. Two vectors that add to nothing to be negatives, or vector inverses. Vector d4 + vector d5 = 0 so vector d4 = -vector d5 and vice versa. Will only work if they have the same magnitude but opposite directions. A minus sign in front of a vector indicates a reversal of the vector"s direction. Vector difference: a vector operation performed by inverting the vector to be subtracted and then adding.