How can acceleration best be defined?

Acceleration is best defined as the rate of change of velocity over time because it specifically describes how quickly an object’s velocity changes. Velocity itself is a vector quantity, meaning it has both magnitude (speed) and direction. Therefore, acceleration indicates not just how fast an object speeds up or slows down but also how its direction may be changing, such as in the case of circular motion.

When discussing acceleration, it is crucial to consider both the time frame over which the velocity changes and the nature of that change (whether it is an increase or decrease in speed, as well as directional changes). This definition encapsulates the core concept of acceleration in physics, emphasizing the relationship between changes in velocity and the time over which those changes occur.

The other definitions provided do not capture the complete nature of acceleration. For example, defining it as the change of speed over distance focuses solely on one aspect of motion and does not account for the time factor or directional changes that velocity encompasses. Similarly, stating that acceleration is the magnitude of force applied is incomplete, as force is related to acceleration through Newton's second law (F=ma), but they are not the same. Lastly, defining it as the constant speed of an object is misleading because constant speed indicates no acceleration at all