Question 51213
actually to answer for this queation we need some more data, like

   whether object is still moving or motionless, and the time "t" is what kind of time ,from where it is measured? like that...



But beyond these quations I can answer U if I've to assume some stuffs.


        if an object travels with acceleration of a, would be in a distance of
        H
    
   where H = u^2+1/2at^2    (u - intial velocity)
       So we don't have any initial velocity as the object free falls,

                  1/2at^2 = h
                  1/2*10*t^2 = 16T^2+70T+8  (gravitational acceleration approx-10)

                            t =((16T^2+70T+8)/5)^(1/2)