Question

A boy walks 4 km east and then turns around and walks 1.5 km west. If east is taken as the positive direction and the west as the negative direction on a number line then what is the distance the boy covers and his displacement?

Answer 1

Step-by-step explanation

First, let us make a sketch of the question:

From the diagram, the blue circle represents his starting position while the black circle represents his final position.

The total distance the boy covers is the sum of his two journeys, to the east and then to the west.

That is:

The boy's displacement is the distance between his starting position and his final position.

Since the west is taken as negative direction and the east taken as the positive direction, it means that 4km east means +4km and 1.5