I'm trying to find the impact or penetration depth of a projectile in the (reasonably) most realistic way possible. I assume this has many factors including velocity, the densities of both materials, shapes of both materials, the medium of which the projectile travels through, gravity, etc. Because I know this could be infinitely complicated by variables, I will be assuming the air will be standard temperature pressure. This should ease finding the air resistance on the projectile. Depending on the necessary equations, I may end up omitting other variables. Thanks in advance to anyone who can help.