Answer:
Step-by-step explanation:
Since we are looking at speed over a time unit, we have an acceleration graph. The definition of acceleration mathematically is:
(that's the change in velocity over the change in time). The slope of any line in this graph wil represent the acceleration. Slope is rise over run, or y over x. Therefore, if acceleration is velocity over time, then the y axis is the velocity axis and the x axis is the time axis. It makes perfect, beautiful sense!!