Nathaniel Fitch, writing at The Firearms Blog, has been doing a series of articles on the fundamentals and some advanced concepts about firearms and ballistics. Past articles have dealt with explaining basic terms and concepts involved in ballistics, and various firearms actions. Today, however, he has published the first of a series of articles on terminal ballistics: the ballistics of what happens after the bullet has struck a target. This is a subject that has interested me. His article today is entitled "Ballistics 201: Introducing a New Way of Thinking About Terminal Effectiveness – Force, Energy, and Work."
While on the subject, you may want to read the FBI report entitled "Handgun Wounding Factors and Effectiveness" (PDF here; HTML--Part 1 and Part 2).