Which object will hit the ground first, the one projected horizontally or the one dropped?

Question

At the instant a horizontally projected object is launched, an identical object is dropped. Which object will hit the ground first, the one projected horizontally or the one dropped? Be sure to explain fully, addressing the relevant underlying material.

Answer 1

This is similar to your other question. Horizontal and vertical motion don't affect each other. So, in terms of only vertical motion, is their initial speed the same or is one starting off faster than the other?