If we can ignore any effects of air resistance ... and we always do ... then it
makes no difference what its horizontal speed was, or whether it had any
at all. It hits the ground in the same time as an arrow that just dropped from
the bow to ground.
The distance an object falls from rest in ' T ' seconds, on account of gravity, is
D = 1/2 G T² . ('G' is the acceleration of gravity, 9.8m/s² )
This arrow falls 1.5 meters,and 1/2 G is 9.8/2 = 4.9 m/s² .
1.5 m = 4.9 m/s² T²
Divide each side by 4.9 m/s² : (1.5 / 4.9) sec² = T²
Take the square root of each side: T = square root of (1.5/4.9) = 0.553 sec
