When you drop an object from some height above the ground, it has an initial velocity of zero. Simple equations allow you to calculate the velocity an object falls after a given period of time and the velocity it reaches at a given displacement. The equations assume that air resistance is negligible.
Vo = initial velocity = 0 (m/s)
x = vertical displacement
t = time and a = gravitational constant = 9.8 meters per second squared (m/s2)
x= initial velocity * time + 1/2 acceleration * time squared = Vot + (1/2)at2]]] = (0*8) + (1/2)(9.8)(8)(8) = 313.6 meters (metric)