What is formula for finding velocity of falling object?

V = Vo + gt

where

Vo is the initial velocity of the object

g is the acceleration of gravity

t is time (Vo is measured when t=0)

NOTE: a positive value for V or Vo means an upward velocity, negative is downward. If the object starts out at rest, Vo is 0. If the object was initially propelled upward and is thus moving upward at time t=0, Vo is positive. If the object is already falling or is shot/pushed/pulled downward, Vo will be a negative number.

NOTE 2: the equation has to be modified by adding a drag factor if subject to substantial drag from the fluid (gas or liquid) it is falling through. In that case the equation gets more complicated.