Well, I can't fault your math (at least, not without some text books handy), but it seems a bit complex for a game rule. I agree that the D&D rules for falling damage are troublingly simple, but this method is probably going too far in the other direction. I suggest some simplification of your rules to enhance ease of use in actual gameplay. After all, no matter how accurate a rule may be, a rule that never gets used is a bad rule.

Regardless, you get an A for effort.