Answer:
Average speed: 0.5 m/s. Average velocity: 0
Explanation:
Average speed is given by:
[tex]v=\frac{d}{t}[/tex]
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,
[tex]v=\frac{400}{800}=0.5 m/s[/tex]
Instead, average velocity is defined as
[tex]v=\frac{d}{t}[/tex]
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.
