What is the total displacement of a dog that runs north 80 meters to chase a ball returns to its master and then runs south W meters?

To find the total displacement of the dog, we first note that it runs 80 meters north to chase the ball, then returns 80 meters south to its master, resulting in no net displacement in the north-south direction at that point. After returning to its master, the dog runs south W meters. Therefore, the total displacement is W meters south from the original starting point.