speed–time graph

A speed–time graph shows how an object's speed (or velocity) changes over time. The gradient of the line indicates the acceleration of the object; if the line is horizontal, the acceleration is zero and the object is travelling at constant speed. If the gradient is positive, the object is accelerating and if negative, decelerating. The area under the graph measures the distance travelled.

Graph used to describe the motion of a body by illustrating how its speed or velocity changes with time. The gradient of the graph gives the object's acceleration. If the gradient is zero (the graph is horizontal) then the body is moving with constant speed or uniform velocity (the acceleration is zero); if the gradient is constant, the body is moving with uniform acceleration. If the gradient is positive then the body is accelerating; if the gradient is negative then the body is decelerating. The area under the graph gives the total distance travelled by the body.