If the rate of increase of velocity of an object is constant or the rate of increase of velocity is always the same per second then the acceleration of that object is called equilibrium acceleration. An example of a balanced acceleration is the acceleration of an object falling freely under the influence of gravity. If an object continues to read freely, its acceleration is 9.8ms-2 , that is, its speed increases by 9.8ms-2 per second when the object is approaching the surface .