kinetic energy is the combo of speed and weight. heavier the arrow, the quieter the bow will be, more accurate, kinetic energy is obviously gonna b more. the lighter the arrow, the nosier its gonna b, and ur kinetic energy is going to drop, mainly bc it has less weight. the heavier arrow is going to react better to the energy from the bow, whereas a lighter arrow isnt gonna store the energy that the heavier one will.
i shoot 3d tourneys w guys that shoot recurves and their arrows weighed about 800grams. the reason being that long bows do not create the arrow speed that compounds do (duh, right?) so they need a heavier arrow to get more penetration.
heavier arrows=more penetration, higher kinetic energy
lighter arrows=the opposite of above...haha im not sayin anything is wrong w using lighter arrows, bc they'll still work, especially w the speeds new bows are producing, but lighter arrow is going to produce less KE, its just basic physics.:darkbeer::darkbeer::darkbeer:
sorry for the long post, hope it helped