The horizontal force and speed have no influence on the vertical force,
speed, or acceleration. This is a fancier way of saying that the behavior
of the ball in the vertical direction has no relationship to its behavior in
the horizontal direction. The ball thrown horizontally and the ball dropped
vertically hit the ground at the same time. Same answer for a bullet shot
from a gun and a bullet dropped from the gun's muzzle at the same time ...
strange as it may seem.
