Originally Posted by
DR015
What you mean, however, is that momentum is more important in the lethality of a cartridge than kinetic energy.?
Yes, quite directly so. Kinetic Energy is converted into several different things in real world, inelastic collisions - and even LOST. Because Kinetic Energy is NOT conserved in real world, inelastic collisions.
Momentum, alternatively, IS conserved. And unlike Kinetic Energy, momentum does not overvalue velocity over mass by squaring the velocity vector - such high KE rounds can "cheat" their way to high KE by traveling very fast, but a bullet cannot lie about its potential when reviewed in terms of momentum, which equally values mass and velocity.
Originally Posted by
Wingbone
Momentum is governed by mass.
Momentum is not "governed by mass." But rather, Momentum is NOT governed by velocity, as is Kinetic Energy. Momentum values mass and velocity equally - if we double mass at the same velocity, we double momentum. If we double velocity at the same bullet mass, we double momentum. For kinetic energy, if we double mass at the same velocity, we double KE, but if we double velocity of the same bullet weight, we quadruple the KE... Which might make sense in terms of overall Work potential (KE(in) vs. KE(out)), but again, since KE is converted to a lot of different forms, AND because KE is LOST in inelastic collisions, we can't actually use KE to quantify work done in inelastic collisions, we have to come back to momentum, and then calculate the KE(out)....