Not sure I understand. If you fire a gun toward the ground from the leaning tower of Pisa, and you drop a bullet at the same time, the bullet that was fired fro

Not sure I understand. If you fire a gun toward the ground from the leaning tower of Pisa, and you drop a bullet at the same time, the bullet that was fired from the gun will reach the ground before the other one. The thing is that the explosion gave the bullet additional momentum toward the ground (and a corresponding inverse momentum to the person holding the gun, more or less, ignoring other factors)