According to the equations of motion, [tex]V = V_0 - g*t[/tex], [tex]-g*t[/tex] is the deceleration due to the gravitational forces. It is assumed to be a deceleration value as the gravity opposes the motion so if the initial velocity, for example, is 10m/s, the body will move until it reaches a point at which the final velocity will be zero and then it will come back. At this point, it will be assumed to be an acceleration as the motion will be in the same direction of the gravitational force.
