The motion of a particle is given by a straight line in the graph given above drawn with displacement (x) and time (t). Which one among the following statements is correct?

In kinematics, the slope of a displacement-time (x-t) graph represents the velocity of the particle. A straight line on such a graph indicates that the slope is constant throughout the motion. Since the slope is constant, the velocity does not change over time, which is the definition of uniform velocity. This corresponds to uniform linear motion, where an object covers equal displacements in equal intervals of time [2]. Conversely, a curved line on an x-t graph would indicate non-uniform velocity or acceleration. While uniform circular motion involves constant speed, it requires a changing velocity due to continuous changes in direction, which cannot be represented by a single straight line on a displacement-time graph. Therefore, a straight-line displacement-time graph uniquely signifies that the velocity of the particle is uniform.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > 8.4 Uniform and Non-uniform Linear Motion > p. 117
2. [2] Science-Class VII . NCERT(Revised ed 2025) > Chapter 8: Measurement of Time and Motion > In a Nutshell > p. 118