If a stone dropped from the top of a tower travels half of the height of the tower during last second of its fall, the time of fail is ( in seconds)

If a stone dropped from the top of a tower travels half of the height

1.	If a stone dropped from the top of a tower travels half of the height of the tower during last second of its fall, the time of fail is ( in seconds)
Answer» `3+sqrt(2)` `4+sqrt(2)` `2-sqrt(2)` `2+sqrt(2)` ANSWER :D