What is acceleration defined as?

Acceleration is defined as the change in velocity of an object over a specific period of time. This concept highlights how quickly an object is speeding up or slowing down. When we consider that acceleration describes how much velocity changes in relation to time, the definition aligns well with the idea that we are looking at changes occurring in time intervals—specifically, how much the velocity changes in one second, making it a clear and accurate representation of the physical quantity being described.

Defining acceleration in terms of changes in velocity during a second allows us to quantify how fast an object is accelerating. This is especially useful in physics, as it helps us analyze motion in various scenarios, like objects in free fall or vehicles speeding up or slowing down on a road.

Other definitions provided in the options, while related to acceleration in their contexts, do not fully capture its definition. Acceleration encompasses both increases and decreases in speed (velocity), thus reinforcing the importance of the broader definition that evaluates the change over time.