We determine the speed of an object from the slope of the distance-time graph. If the graph is steep then it has a high slope. This means that that the object is moving at high speed. If the graph is a horizontal line, its slope is zero. This means that the object is at stationary position. If the slope of the graph is positive, it means that the object is moving away from its starting point and if the slope is negative, it indicates that the object is returning to its starting starting point.