What term describes the rate at which velocity changes?

The rate at which velocity changes is defined as acceleration. This term refers to the change in velocity per unit of time, indicating how quickly an object speeds up, slows down, or changes direction. When an object experiences a change in its speed or direction, the value calculated as the change in velocity divided by the time taken for that change is known as acceleration.

In this context, it is important to note that deceleration is a specific type of acceleration that refers to a decrease in velocity. However, acceleration encompasses both increases and decreases in velocity, making it the broader and more accurate term for any change in velocity over time. Similarly, momentum refers to the quantity of motion an object has, dependent on both its mass and velocity, and force is an external influence that can cause an object to accelerate. Hence, acceleration is the term that directly addresses the rate of change in velocity.