ORIGINAL: TFOX
Sylvan,I actaully agree with you but you are forgettiong or not adding1 major factor of the equation,EFFICIENCY.It is possible for a bow to shoot a lighterarrow more efficiently than a heavy one,although,NOT very likely.(plus,I have NEVER seen it happen personally)
If the heavy arrow is requiring more force to accelerate it than the cams and bow can eficiently drive, then it will lose energy.
YES,in MOST EVERY case,the lighter arrow shot from a bow will lose energy due to wasted energy but ifa higher amount of the stored energy can be put into a lighter arrow,than a heavier one,it will fly faster than normal,therefore increasing the ke,momentum probably won't be more but ke will be.
So for arguments sake,it is possible but not likely.So the always imo,is not true,except in theory.[:-]
I certainly didn't forget efficiency, in fact in my very first post I explained that the reason heavier arrows carry more ke than lighter arrows is precisely because bows shoot heavier arrows more efficiently than lighter ones. Here's the quote...
"Going to a heavier arrow ALWAYS results in an increase in both momentum and kinetic energy. The reason for this is that,upon release,stored potential energy in the limbs is transferred more efficiently to the kinetic energy of arrows of greater mass than of lower mass. That's just fundamental mechanics and the rule can't be violated."
Heavier arrows absorb more of the stored potential energy in the limbsand the ratio of energy absorbed/energy storedis the definition of efficiency. That is the rule that can't be violated. It's ALWAYS true. If test results indicate otherwise than something is amiss or something unaccounted for is going on. If the only change is to increase arrow mass then ke and momentum will ALWAYS increase.
Oh and by the way, it is impossible to increase the ke without increasing momentum and vice versa by only making one change e.g. arrow mass or bow weight or draw length etc.