The position equation is h(t) = -16*t^2 + v*t +, where t is the time in seconds; h(t) is the height over the ground level, in feet; v is the initial vertical velocity, in ft/s; and is the initial height, in feet. So, in your case, the position equation is h(t) = -16*t^2 + 30*t + 5.8.