The following figure represents the velocitytime graph of a moving car on a road: Which segment of the graph represents the retardation?

In a velocity-time (v-t) graph, the slope or gradient of the line represents the acceleration of the object [1]. A positive slope indicates that the object is accelerating, meaning its velocity is increasing over time [1]. Conversely, a negative slope (downward sloping) indicates that the object is decelerating, which is also known as retardation [1]. Retardation occurs when the final velocity is less than the initial velocity, resulting in a negative rate of change. Based on standard v-t graph conventions, segment AB represents acceleration (positive slope), segment BC represents uniform motion with constant velocity (zero slope), and segment CD represents retardation as the velocity decreases toward the time axis (negative slope) [1]. Therefore, segment CD is the correct representation of retardation.

Sources

1. [1] https://satheeneet.iitk.ac.in/article/physics/physics-velocity-time-graphs/