A stone is dropped from the upper observation deck of a tower 400 m above the ground Assume g 9 8 m s a Find the distance in meters of the stone above ground at time t s t b How long does it take the stone to reach the ground Round your answer to two decimal places S c with what velocity does it strike the ground Round your answer to one decimal place m s d If the stone is thrown downward with a velocity of 5 m s how long does it take to reach the ground Round your answer to two decimal places