Mathematics for Electrical Engineering and Computing

9

Vectors

9.1 Introduction

Many things can be represented by a simple number, for instance, time, distance, mass, which are then called scalar quantities. Others, however, are better represented by both their size, or magnitude, and a direction. Some of these are velocity, acceleration, and force. These quantities are called vector quantities because they are represented by vectors.

A simple example of a vector is one that describes displacement. Supposing someone is standing in a room with floor tiles (as in Figure 9.1) and moving from one position to another can be described by the number of tiles to the right and the number of tiles towards the top of the page.

Figure 9.1 A tiled room. To reach the cupboard from the door we need to move four tiles ...