RE: Did you know a heavier arrow drops LESS than a lighter arrow??
Well, at 30 yards, I'd have to agree with Rack. Beyond that though... Yes, I've known that since 1989 when I had my bow set up with an overdraw. I was shooting 2216's and decided to try 2213's. Everybody was shooting 2213's for 3D (speed, don'tcha know), and I thought I needed to do the same in order to stay competitive.
When I got the bow tuned and sighted in for the 2213's, my pin gaps were much wider than they were with the heavier arrow. The distance between my 20 pin and 60 pin had gone from 7/8" to 1 1/8".
Fortunately, it only took a week to destroy that dozen 2213's and I was back to the 2216's. But that's what got me very interested in the subject of downrange retained energy with various arrow weights.
By the way, I'm only talking a 60 grain difference between those two arrows. Two arrows with a much wider difference in weight will have widely different trajectories. The light arrow will have a much flatter trajectory. The heavy arrow will hit much harder, even though you might have time to sit and drink a cup of coffee while watching it go downrange.