Material strength: an impact experiment: [url]http://mw.concord.org/modeler1.3/mirror/materials/bullet.html[/url] [img:30614b1d45]http://mw.concord.org/modeler1.3/mirror/materials/bullet.gif[/img:30614b1d45][img:30614b1d45]http://mw.concord.org/modeler1.3/mirror/materials/bullet2.gif[/img:30614b1d45]