A circular test track for cars has a circumference of 2.7km . A car travels around the track from the southernmost point to the northernmost point. What distance does the car travel? (answer 1.35km). Part B !!!!!!!What is the car's displacement from its original position?,

This problem is about the difference between distance and displacement.
The distance is how many kilometers has the car covered, the displacement is how far from the original point is the car now, and does not depend on the path followed, but it is the shortest path that connects two points.

a) In this part, they ask you for the distance. From the southernmost to the northernmost point of the circumference, the car has traveled half of the circumference, therefore:
distance = circumference ÷ 2 = 2.7km ÷ 2 = 1.35km

b) In this part, you are asked for the displacement, which in this case is the diameter of the circumference:
displacement = diameter = circumference ÷ π = 2.7km ÷ 3.14 = 0.86km = 860m