EA particle is dropped from the starting height $$y = 0$$ at the time $$t = 0$$: $$y(0) = 0$$. The distance traveled $$y(t)$$ within time $$t$$ is given by the following distance-time law:$$y(t) ~=~ \frac{1}{2} \, g \, t^2$$Here $$g = 9.8 \, \frac{\mathrm m}{\mathrm{s}^2}$$ is the gravitational acceleration on Earth.