Question

At the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. which ball hits the ground first?

Answer 1

the one that was dropped

Answer 2

Both will hit the ground simultaneously because the vertical component of the motion of the ball that was thrown horizontally is completely independent of the horizontal component of its motion. So with respect to vertical motion, both balls are seen to be dropped and falling vertically together.