Answer:
The total displacement of a dog is 100 m.
Step-by-step explanation:
Given that,
A dog that runs north 80 meters to chase a ball, returns to its master, and then runs south 20 meters.
We can define the displacement as the distance between the initial position and final position of the object.
The displacement is defined as,

Put the value into the formula


Hence, The total displacement of a dog is 100 m.