WAEC Physics 2013 Paper

Concept:The slope of a distance–time graph gives the rate of change of distance with time.Explanation:For a straight-line graph, the slope is the vertical change divided by the horizontal change.In a distance–time graph, distance is plotted on the vertical axis and time on the horizontal axis.So, slope $= \frac{\text{change in distance}}{\text{change in time}} = \frac{\Delta d}{\Delta t}$.This rate is the definition of speed.The graph uses distance, not displacement, so the slope measures speed rather than velocity.Answer:C. speed