AQA GCSE Physics Paper 2 Practice Exam 2025 - Free AQA GCSE Physics Practice Questions and Study Guide

Acceleration is defined as the rate of change of velocity with respect to time. Velocity is a vector quantity that includes both speed and direction, meaning that any change in speed or direction results in a change in velocity. Therefore, acceleration measures how quickly an object is speeding up, slowing down, or changing direction.

In contrast, while speed is related to how fast something is moving, it does not account for changes in direction. As for the rate of change of distance, this is more accurately described as speed rather than acceleration. Lastly, the rate of change of force is not relevant to the definition of acceleration, as force relates to the interaction that causes objects to accelerate rather than defining what acceleration is. Thus, the most comprehensive and correct description of acceleration is indeed its relation to the change in velocity over time.