For an object moving in a plane with constant acceleration, what is true about its velocity vector?
In motion with constant acceleration in a plane, the velocity vector changes in magnitude and/or direction over time because the acceleration continuously alters it. Unlike uniform motion, the velocity is not constant unless the acceleration is zero. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives It changes in magnitude and/or direction as the result, so option D is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Acceleration and Velocity Analysis - Part 8