As long as the only force is the gravitational force, then the acceleration is the acceleration due to gravity, g. At Earth’s surface the value is 9.8 m/s2. (In the English system g = 32.2 ft/s2.) If the object is dropped from rest at time t = 0, then the velocity at a future time t is simply v = gt. That is, the velocity increases by 9.8 m/s each second. If we measure the distance fallen from the position where it was dropped, then at time t it has fallen a distance d = 1/2 gt2. The following table shows velocity and distance fallen for some selected times.