A runner traveled 15 kilometers north then backtracked 11 kilometers south before stopping. His resultant displacement was:

26 km south

4 kilometers south

4 kilometers north

26 km north

Answer

4 kilometers north

Explanation

The displacement of is vector quantity. It has both magnitude and direction.

Taking the displacement towards north to be positive, the displacement towards south would be negative.

∴ Total displacement = 15 + (-11)

= 15 - 11

= 4 Km