How can deceleration be defined?

Deceleration is accurately defined as the reduction in the velocity of a moving body with respect to time. This concept is closely tied to the mathematical definition of acceleration, where acceleration is the rate of change of velocity with time. When we discuss deceleration specifically, it indicates that the velocity of an object is decreasing—meaning that the object is slowing down over a certain period.

In practical terms, this could apply to scenarios such as a car coming to a stop or an aircraft reducing its speed before landing. The emphasis on "with respect to time" highlights the fact that deceleration considers not just the change in speed but also how quickly that change occurs, which is a crucial aspect in the study of motion in aerodynamics and other fields. In contrast, other options either imply an increase in speed or do not incorporate the element of time, making them less accurate definitions of deceleration.