A circular racetrack has a radius of 500 m. What is the displacement of a bicyclist when she travels around the track from the north side to the south side? When she makes one complete circle around the track? Explain.

The radius of racetrack is r=500 m.

In Simple words displacement is the shortest distance travelled by an object.

Here in first casebicyclistis travelling from A to B that is a semicircle.

So, the distance traveled by thebicyclistwill be πR.

Now the displacementtraveledis the minimum distance between point A and B that is diameter AB.

$$\begin{gathered} Displacement=AB \\ =2R \\ =2\left(500m\right) \\ =1000m \end{gathered}$$

Thus, the displacement is 1000 m.

When the body is completing one full rotation the distance traveled by the body is 2πR.

The displacementtraveledwill be the minimium distance between point A and B.

As it completes one circle the point A and B will be same .

So, the displacement between the points will bezero.

Therefore, displacement of bicyclist in case II is zero.