What is defined as the rate of change of displacement?

Velocity is defined as the rate of change of displacement, which involves not only how fast an object is moving but also the direction in which it is moving. Displacement is a vector quantity that refers to the change in position of an object and includes both the distance and direction of that change. Since velocity is a vector, it provides a complete picture by specifying both magnitude (speed) and direction.

Understanding the distinction between velocity and speed is crucial; while speed is a scalar quantity that only measures how fast an object is moving regardless of its direction, velocity incorporates directional information. This means that if an object changes its direction, its velocity changes even if its speed remains constant. Therefore, when discussing the rate of change of displacement, velocity is the accurate term to use.