Question

A particular circular track on level ground has a circumference of 400 m. a walker, traveling counterclockwise and starting at the southernmost point of the track, completes one lap in 800 s, ending his circular trip by arriving again at the southernmost point. find the average speed and the average velocity for the walker's trip around the track.

Answer 1

Average speed: 0.5 m/s. Average velocity: 0

Step-by-step explanation:

Average speed is given by:

`v=(d)/(t)`

where

d is the total distance covered (the length, of one lap of the track, so d = 400 m)

t is the time taken to cover that distance (so, t = 800 s)

Substituting,

`v=(400)/(800)=0.5 m/s`

Instead, average velocity is defined as

`v=(d)/(t)`

where this time,

d is the displacement, which is the vector connecting the starting point to the final point of the motion

t is still the time taken (800 s)

However, in this case the walker starts and finishes his trip at the same point: therefore, the displacement is zero (d=0), and this means that the average velocity is zero as well.