Show how the displacement of a runner changed during a sprint race.draw a displacement-time graph to show this data, and use it to deduce the runner's speed in the middle of the race.
Displacement (m) 0 4 10 20 50 80 105,
Time(s) 0 1 2 3 6 9 12.
Plot it.
speed at middle of race is the slope of the graph.
You will have to decide what "middle" of race means...at six seconds, or at 52.5 meters.