What is the definition of velocity?

Velocity is defined as the total displacement of an object, which is a vector quantity. This means that velocity not only considers how far an object has moved, but also the direction of that movement. Displacement is defined as the shortest straight line distance from the starting point to the ending point, taking into account the direction, rather than just the path traveled.

In contrast, the other options focus on different aspects unrelated to the complete definition of velocity. For instance, speed is a scalar quantity that describes how fast an object is moving without regard to direction, so it does not encompass the full meaning of velocity. Similarly, the change in distance (from one point to another) per unit of time refers more to speed than to velocity, as it omits the directional component. Lastly, while the distance traveled in a time interval pertains to how far an object has moved, it also lacks the directional aspect necessary for defining velocity properly. Thus, the definition of velocity correctly emphasizes both displacement and direction.