A vector quantity can be represented graphically by a line, drawn so that:
- the length of the line denotes the magnitude of the quantity, and
- the direction of the line denotes the direction in which the vector quantity acts.
An arrow is used to denote the sense, or direction, of the vector. The arrow end of a vector is called the ‘nose’ and the other end the ‘tail’.
For example, a force of 9Nacting at 45o to the horizontal is shown in Following figure.
Note that an angle of+45o is drawn from the horizontal and moves anticlockwise. A velocity of 20m/s at −60o is shown in Following figure. Note that an angle of −60o is drawn from the horizontal and moves clockwise.