From DT Online

Vectors are Forces which are defined by both magnitude and direction.

Resultant and Equilibrant

Vectors can be represented by lines drawn to scale providing we know:

  • the magnitude
  • the point of application
  • the line of action
  • the direction

For example, from any point O as shown, a line can be draw to a scale representing an upward pointing force of 2 newtons and similarly from the same point, a shorter line to represent the downward pointing force of 1 newton.

Common sense tells us in such a simple example that these two opposing forces could be replaced by a single 1 newton. force pointing upwards from point O (i.e. the Resultant) and the point O could be held still by an equal and opposite, downwards pointing 1 newton force (i.e. the Equilibrant).