Acceleration is the rate at which an object changes its velocity. Velocity is the movement of any object which is measured in metres per second. It is also called as speed. The rate of change in this velocity (speed) is called the acceleration. If the speed (velocity) of a moving object increases, then the object is said to be accelerating. If the speed of the moving object decreases, then the object is said to be decelerating. Below is the acceleration formula to find the acceleration with velocity and time.