How is the change of position defined for units of measurement?

Velocity is defined as the change of position of an object with respect to time. It specifically considers both the distance an object travels and the direction of that travel, providing a vector quantity that signifies how fast an object is moving and in which direction. This makes it distinct from other terms that relate to motion.

Displacement is actually the straight-line distance between the initial and final positions of an object, including the direction of that line. While related, displacement doesn't account for time in the same way that velocity does. Acceleration measures the change in velocity over time, but it does not directly refer to position. Volume pertains to the amount of space an object occupies, which is unrelated to changes in position.

So, velocity is the correct answer as it encompasses both the change of position and the factor of time, effectively addressing how quickly and in what direction an object moves from one point to another.