In a free-fall motion, the distance covered by the object in free fall is given by:
[tex]S= \frac{1}{2}gt^2 [/tex]
where g is the gravitational acceleration and t is the time taken to cover a distance S. In this case, the distance S is the height h from which the ball has been dropped: to find its value, we can substitute t=2.0 s into the formula, and we get
[tex]h= \frac{1}{2}(9.81 m/s^2)(2.0s)^2=19.6 m [/tex]
