Thank you Arthur P. Well here the word direct is added and that makes a big difference from what was said earlier. Its a far cry from "...an arrow's Kinetic Energy tells one absolutely nothing about how well it will penertrate..." Although I think the statement that "KE has no direct bearing on penetration" is misleading it is not incorrect. Although it is true that KE is a scalar quantity while momentum is a vector quantity it is also true that as momentum increases so does KE and as momentum decreases so does KE so the implication here is misleading because he is also implying that momentum is THE indicator while KE plays almost no role. The tuning fork comparison is far from compairing 2 arrows shot from the same bow. I have yet to see an arrow carrying say 50 ft/lbs of KE simply stay in one position and vibrate! For all intent and purpose when refering to KE of an arrow it is a vector quantity.

Thanks for the link! I think you gave me this link once before but I was unable to open it. I don't have time right now but I will give it a try later. Thanks again!