Describing the motion of an object can be difficult to do and using graphs make motion easier to understand. motion is a change in position measured by distance and time. speed tells us the rate at which an object moves. speed graphs are distance-time graphs; sometimes people label them as position-time graphs as well. time is plotted on the x-axis and distance or position on the y-axis of a line graph. a distance-time graph tells us how far an object has moved with time. • the steeper the graph, the faster the motion. • a horizontal line means the object is not changing its position. it is not moving, and it is at rest. • a downward sloping line means the object is returning to the start. use the text and the graphs above to choose all of the correct answers concerning speed? in both graphs, speed will be measured in meters/second. in graph a, the object travelled a distance of 40 meters in 4 seconds the total distance travelled by the object in graph b is greater than the object in graph a. in graph b, the object is at rest for 5 seconds. the object in graph b was moving at a greater speed than the object in graph a