Question

The three graphs represent the progress of three runners in a 400-meter race. The solid line represents runner A. The dotted line represents runner B. The dashed line represents runner C.A runner stopped running for a while. Which one? During which interval of time did that happen?

Answer 1

Looking at the graph, the y axis represents distance while the x axis represents time. The line on the graph represents change in distance with respect to time. For the solid line which represents runner A, at the distance just above 300, the line is horizontal. This means that diatance was not changing with time. This tells us that Runner A stopped running during that period. The time interval is lies between the time corresponding to the beginning of the horizontal line and the end. Thus, the time interval is between 15 seconds and 45 seconds

Thus,

Runner A stopped running

Time interval is between 15 seconds and 45 seconds