A vector is a physical quantity which has both magnitude and direction. Magnitude of a physical quantity is simply the measure or the number calculated for the quantity. Direction of a vector implies the direction of the resultant vector, usually taken from the initial starting point to the final point. Displacement is one such example of a vector quantity since it has both magnitude and direction. We can find the resultant displacement vector by joining the starting point to its ending point.
Example 1: Lucy walked 7m towards east and then walked 10m towards west. Determine Lucy’s resulting displacement?
Given: Displacement of Lucy in east (or right) direction = 7m
Displacement of Lucy in west (or left) direction) = 10m
Let right direction be represented as +7m and left direction be represented as -10m.
Hence, resulting displacement = 7m – 10m = -3m
This implies that the resulting displacement of Lucy is 3m towards west!
Example 2: Brian travelled 20m up north and then travelled 15m down south. Determine Brian’s resulting displacement?
Given: Displacement of Brian in north (or upward) direction = 20m
Displacement of Brian in south (or downward) direction = 15m
Let upward direction be represented as +20m and downward direction be represented as -15m.
Hence, resulting displacement = 20m – 15m = 5m
This implies that the resulting displacement of Brian is 5m up north!