The changes in the distance covered by an object during a time interval are shown in the graph. The graph is split into three sections: I, II, and III. In which section of the graph does the object have a speed of zero? (a) There are no sections of the graph in which the speed is zero, (b) II, (c) III, or (d) I.
The graph shows distance on the vertical axis and time on the horizontal axis. The distance covered by the object increases during section I, remains the same during section II, and then increases again during section III. The key point to remember here is, on a distance–time graph, a flat line with a slope of zero indicates zero speed. The section of the graph in which the slope is zero is section II. And so the answer to the question “In which section of the graph does the object have a speed of zero?” is (b) II.