The positive work a bullet does in penetrating an animal is manifested in the distance the bullet travels through the animal. The work done is described in terms of ENERGY. More work means more energy expended.

The work done is a measurement of force thru a distance, with force associated with the change of momentum(mass x velocity)occuring.

http://en.wikipedia.org/wiki/Force

What type of work the bullet does is related to the bullet characteristics. Large "solid" FMJ bullets of similar energy penetrate less than identical smaller diameter bullets of the same energy working against similar resistance. Thus some "types" of bullet work are better than others at accomplishing the desired result. Give me the one than penetrates enough with the largest diameter at a given energy level, please.

The animal performs negative work in stopping the bullet.Tougher game implies more resistance to the bullets required. Soft points work great on whitetails but not on Ele. If the animal'negative work cannot equal the positive work of the bullet, the bullet penetrates the animal and the negative work is finished in the gound or elsewhere.

What concerns us is how the work is performed satisfactorily by a certain bullet at a certain velocity.Which bullet/velocity combo is best??

Thank goodness empiric observation and deduction do quite well without a physics approach. Fun to consider though!!