What happens to mutually contra-aimed projectiles, if fired simultaneously?

Question

Two guns (let us say, cannons) are directly aimed at each other and fired at exactly the same moment. The cannonballs have identical air resistances, however, the initial velocities are not necessarily identical. What will happen to them?

Answer 1

The cannonballs will collide! No matter if the initial velocities did not match, or the cannons were not on the same altitude above the ground-plane.

Reason: at the time of collision, the two cannonballs have been travelling for the same amont of time. Therefore, since the vertical acceleration away from the initial line of aim is only proportional to time, they have each fallen an identical distance away from that line, and they collide.Exactly where, depends on their relative firing velocities. But not if!

Suggestion: do not try this experiment yourself. The consequences of slight misaim are significant.

-- Cheers, -- Mr. d.