Final answer:
Hannah's displacement is 0 meters because she ended her journey at the starting point, leading to no net change in her position.
Step-by-step explanation:
Hannah's displacement is the change in her position from the start of her journey to the end. Displacement is a vector quantity, meaning it has both a magnitude and a direction. Since Hannah walks to the store and then returns back home, her final position is the same as her starting position. Thus, despite the fact that she walked a total distance of 1000 meters (500 meters to the store and 500 meters back home), her displacement would be 0 meters since there was no change in her position from start to finish.
The correct answer to the question 'What is Hannah's displacement if she walks 500 meters to the store and back home?' is a. 0 m.