ORIGINAL: Sniper151
Longer draw length will increase kinetic energy but not necessarily speed. A longer draw length will require a stiffer spine arrow and added weight. A archer shooting a 28" arrow at 65 lbs. will have a faster arrow speed than a person shooting a 32" arrow at the same weight, but the longer draw will have the advantage in kinetic energy.
Not necessarily so. Longer length may need a stiffer spine, but the stiffer arrow may not necessarily be heavier. It could be a different arrow altogether. Larger diameter and thinner walls (carbon or aluminum doesn't matter). So the stiffer arrow could be cut and/or adjusted for the same mass weight. That's the only way you can compare the results of a longer draw length. Regardless of what arrow is used in either length it's mass weight has to remain the same.