Answer:
Total displacement = 0 blocks
Step-by-step explanation:
Displacement : It is defined as the total distance between the initial and the final positions of the moving object or a body. The total displacement can be 0 in case the initial and the final positions of the body are same.
The distance traveled by Johnny from his house to his friends house = 4 blocks
Then he immediately returns to his house, so the total distance then covered = 4 blocks
Total distance traveled = 4 + 4
= 8 blocks
But the initial position of Johnny is his house and the final position of Johnny is also his house
Therefore, the initial and the final position of Johnny is same and this can be used as a reference point for the given problem.
⇒ Total displacement = 0 blocks