What is the term for the rate of change of velocity?

Acceleration is defined as the rate of change of velocity over time. When an object's velocity changes—whether it is speeding up, slowing down, or changing direction—acceleration describes how quickly that change is occurring. It is typically measured in units such as meters per second squared (m/s²). The concept of acceleration is crucial in understanding the behavior of objects in motion as it quantifies how velocity changes with time.

Other terms in the question, like speed, refer specifically to how fast an object is moving, but do not take into account the direction or the change in that speed over time. Force measures the influence that causes an object to change its motion, while momentum is the product of an object's mass and velocity, indicating the quantity of motion it possesses. Each of these terms relates to motion but is distinct from the concept of acceleration as the measure of changing velocity.