Alexis walks 10 km west to the grocery store. She shops, then walks back 10 km east to her house.

What distance did she cover? What was her displacement?

A. Distance = 100 km, Displacement = 20 km
B. Distance = 20 km, Displacement = 0 km
C. Distance = 0 km, Displacement = 20 km



Answer :

To solve this problem, let's break it down into the two parts: distance covered and displacement.

1. Distance Covered:
- Alexis walks 10 km west to get to the grocery store.
- After shopping, she walks 10 km back east to return to her house.
- To find the total distance covered, we add the distances for each leg of the journey:
[tex]\[ \text{Total Distance} = 10 \, \text{km (to the store)} + 10 \, \text{km (back home)} = 20 \, \text{km} \][/tex]

2. Displacement:
- Displacement is the net change in position, which is a vector quantity that gives the shortest distance between the starting and ending points, along with the direction.
- Alexis starts at her house and ends up back at her house.
- Since she starts and ends at the same point, the net change in position is zero.
[tex]\[ \text{Displacement} = 0 \, \text{km} \][/tex]

So, the total distance covered is 20 km, and the displacement is 0 km.

Therefore, the correct answer is:
```
distance = 20 km, displacement = 0 km
```