In ncert notes for Class 11 Physics Chapter 4 Only a single coordinate determines the position of each item in one-dimensional motion. Only one plane out of three depicts the movement of an object with respect to the starting point or origin in this sort of motion. Some instances are as follows: an automobile moving in a straight line, a train moving in a straight line, a man cycling on a straight road, an object falling on the ground in a straight line due to gravity