I've been wondering about this for quite some time, and I was hoping I'd get some answers here. Well, here goes: 2 projectiles (bullets) enter the same homogeneous medium (let's say concrete) at a 0 degree angle. Both projectiles have identical impact velocities, however, "Projectile 2" has a mass twice that of "Projectile 1", while maintaining identical sectional densities. Therefore the second projectile would have a frontal surface area twice that of the first projectile. Projectile 2 has twice the momentum and kinetic energy compared to projectile 1, but by the time it would have penetrated the medium, it would have destroyed twice the amount of concrete as projectile 1. Both projectiles are have a pointed nose. My question is, would both projectiles leave at same velocity upon penetrating, or would the heavier projectile leave at a higher velocity? Also, would the nose shape matter? Any insight you may have would be greatly appreciated, and I apologize if I'm asking a lot.