Final answer:
The approximate velocity of the runner at t=1s is 9 m/s.
Step-by-step explanation:
To calculate the approximate velocity of the runner at t=1s using central difference, we need to find the difference in distances at adjacent intervals and divide by the difference in time.
Let's find the difference in distances first:
Δx = x2 - x0
Δx = 9 - 0 = 9 meters
The difference in time is 1s - 0s = 1s.
Now, we can calculate the velocity:
velocity = Δx / Δt
velocity = 9 meters / 1s = 9 m/s