Acceleration

In physics, acceleration is a measure of how fast and in what direction an object's speed and direction of motion are changing. It is defined as the rate of change of the velocity. Like velocity, acceleration has a magnitude and a direction, making it a vector quantity. The SI unit for acceleration is metre per second squared (m⋅s, m/s). The tangential acceleration of an object is the component of the acceleration which is in the same direction as the motion (or tangential velocity) of the object.