distance–time graph

In a distance–time graph distance travelled by an object is plotted against the time it has taken for the object to travel that distance. If the line plotted is straight then the object is travelling at a uniform rate. The line curving upward shows acceleration; a curve downwards plots deceleration.

Graph used to describe the motion of a body by illustrating the relationship between the distance that it travels and the time taken. Plotting distance (on the vertical axis) against time (on the horizontal axis) produces a graph, the gradient of which at any point is the body's speed at that point (called the instantaneous speed). If the gradient is constant (the graph is a straight line), the body has uniform or constant speed; if the gradient varies (the graph is curved), then so does the speed, and the body may be said to be accelerating or decelerating. The shape of the graph allows the distance travelled, the speed at any point, and the average speed to be worked out.