Question

A circular test track for cars has a circumference of 4.7 km. A car travels around the track from the southernmost point to the northernmost point. What distance does the car travel? What is the car's displacement from its original position?

Answer 1

Well, for the distance traveled, the car goes from the northernmost point to the southernmost point. So, it travels half of the circle's circumference = 4.7/2 = 2.35 km.

For the displacement, by going from the northernmost point to the southernmost point, the car basically just travels the diameter of circle.

So, using the formula: Circumference = 2πr = πd

Hence, the d = C/π = 4.7/π = 1.49605... = 1.5 km (2 significant figures)
Therefore, displacement = 1.5 km