if the bullet drop in free fall at the same time as the other fire from a cannon ball with a speed iniatial 2m / s from the top of the cliff 20 meters above BodenKönnen of the solution for this. I know that the X-component of the Bowling Bowl is negligible, but I can not find the relationship between the Y-component of the freefall and pulled the bowling ball bowling ball cannon.

The “x” and “y” of that problem are irrelevant, the distance across has nothing to do with gravity unless the bowling ball is fired at an angle other than 180 (straight across) everything falls at 9.8m/s/s.
As long as the bowling balls are dropped from the same height. As soon as the second bowling ball leaves the cannon it will be in free fall as well and as I stated everything no matter what mass falls at 9.8m/s/s.
Well how far are you dropping the ball in the free fall?
They won’t. The one fired from the cannon will have a little further to fall because of the curvature of the earth.