Answer:
v= 6km/h - 1km/h^2 * t
Step-by-step explanation:
From the information, it seems the runner is slowing down because the speed at 1st hour is 5km/h but at 3rd hour becomes 3km/h.
If v= velocity, v0= initial speed, t= time, and the a=acceleration then the function would be:
v= v0 + a * t
To find the acceleration you need to do this equation:
acceleration= velocity1- velocity3 / t3-t1
a = (3km/h-5km/h)/ (3 hour- 1 hour)
a = (-2km/h)/2hour= -1 km/hour^2
After that, you need to find the initial speed. Try to put the 1st-hour variable into the full equation. It would look like this
v= v0 + a * t
5km/h= v0 + (-1 km/hour^2 * 1 hour)
v0= 5km/h + 1km/h
v0= 6km/h
Then the full function would be:
v= 6km/h - 1km/h^2 * t
The graph would look like a backslash(\) from 5 gradually go down to 1.
6
5 O
4 O
3 O
2 O
1 O
1 2 3 4 5
