Need help with a Catapult Game

I have gone through countless tutorials and examples on gravity and physics for Flash MX, and so far i have nothing. What I’m trying to do is create a catapult game.

The catapult will be stationary at the bottom left of the screen and a power meter will tell you how much “power” you have to launch your projectile. All of the tutorials I have looked at use many variables to calculate where and what velocity a projectile is “flying” through the air. All I want is one variable that is constaly changing (the power meter)

Basically the Power meter will go from 0 to 10 and then back. When at the middle posistion (5) the projectile will land on the target, at 0 it will fall to short, and at 10 it will go past the target.

If anyone has played the game by N-Storm “Frogapult”, this is similar to the type of game I’m hoping to make. Any help or links to tutorials would greatly be appreciated.

Here’s a link to a screen shot of the game “frogapult”. Just looking at it pretty much explains how everything would work.