What is the definition of acceleration?

The definition of acceleration is accurately characterized as the rate of change of velocity with respect to time. This means that acceleration not only involves a change in speed but also includes changes in the direction of motion. Velocity is a vector quantity, which means it has both a magnitude (speed) and a direction. Therefore, when discussing acceleration, it’s important to take into account any changes in both aspects.

When we say that acceleration is the rate of change of velocity, we acknowledge that it can occur in several ways: an increase in speed (positive acceleration), a decrease in speed (negative acceleration or deceleration), or a change in direction while traveling at a constant speed (which still results in a change in velocity). This definition comprehensively captures the essence of acceleration in physics, as it encompasses all possible scenarios of motion.

In contrast, the incorrect options do not fully encompass the definition of acceleration. For instance, defining acceleration merely as the rate of change of speed overlooks the critical factor of direction. Similarly, the notion of change in distance over time does not account for the vector nature of motion, and stating that acceleration is simply an increase in velocity without direction misses the fundamental principle that velocity encompasses both speed and direction.