Acceleration is the rate at which velocity changes. It is also a vector, meaning that it has both a magnitude and direction. The SI unit for acceleration is meters per second squared. Acceleration can...Acceleration is the rate at which velocity changes. It is also a vector, meaning that it has both a magnitude and direction. The SI unit for acceleration is meters per second squared. Acceleration can be caused by a change in the magnitude or the direction of the velocity, or both. Instantaneous acceleration is the slope of the velocity-versus-time graph.
