If a stone with an original velocity of 0 is falling from a ledge and takes 8 seconds to hit the ground, what is the final velocity of the stone? A. 39.2 m/s B. 42.6 m/s C. 78.4 m/s D. 156.8 m/s

Getting the final velocity of a free fall, we need to use this formula:

vf = g * t

where

g = 9.8 m/s^2

t = time

From the problem given, the final velocity of the stone is

vf = g * t

vf = 9.8 m/s^2 * 8 s

vf = 78.4 m/s

So the correct answer is letter C. 78.4 m/s