To find the resultant displacement of the bus, we need to calculate the net displacement by combining the individual displacements in both the horizontal (east/west) and vertical (north/south) directions.
Let's assume that the south direction is negative (-) and the north direction is positive (+) in the vertical axis, while the east direction is positive (+) and the west direction is negative (-) in the horizontal axis.
Southward displacement: The bus travels 20 km south, which means a displacement of -20 km in the vertical direction.
Eastward displacement: The bus then travels 10 km east, resulting in a displacement of +10 km in the horizontal direction.
Northward displacement: Lastly, the bus travels 5 km north, resulting in a displacement of +5 km in the vertical direction.
To find the net displacement, we add the displacements in the vertical and horizontal directions separately:
Vertical displacement: -20 km + 5 km = -15 km (southward direction)
Horizontal displacement: +10 km (eastward direction)
Therefore, the resultant displacement of the bus is 10 km east and 15 km south.