Читать книгу RF/Microwave Engineering and Applications in Energy Systems - Abdullah Eroglu - Страница 15

A scalar quantity gives us a single value of some variable for every point in space such as voltage, current, energy, and temperature. A vector is a quantity which has both a magnitude and a direction in space. Velocity, momentum, acceleration, and force are examples of vector quantities. A mathematical representation of a vector is given in (1.1).

(1.1)

A vector can be represented as a directed line segment, as shown in Figure 1.1.

In Figure 1.1, the magnitude of the vector is given by |A|. The unit vector which defines the direction of the vector is given by

(1.2)

You may consider falling snowflakes as an example for a vector which has direction and magnitude.