A person sitting on the top of a tall building is dropping balls at regular intervals of one second.Find the positions of the 3rd,4th and 5th ball when the 6th ball is being dropped.

When the sixth ball was dropped, 5 seconds have elapsed
from the time the first ball was dropped, 4 seconds after the
second ball was dropped, 3 seconds after the the third ball was
dropped, 2 seconds after the fourth ball was dropped and 1 second
after the fifth ball was dropped.

Thus being said, when the sixth ball was dropped & since the 3rd ball
has been falling for 3 seconds, then

D3 = (1/2)(9.8)(3^2) = 44.1 meters

Since the fourth ball has been falling for 2 seconds,

D4 = (1/2)(9.8)(2^2) = 19.6 meters

and since the fifth ball has been falling for 1 second,

D5 = (1/2)(9.8)(1)^2 = 4.9 m