Hiya,
For an easier way, I think you will need a combination of an animation and physics.
I tried to experiment with this and if you check the .capx you'll notice it isn't easy to program it.
Or at least not for me :)
mediaconceptfactory.com/test/Bounce.capx
So what I'd try and do is; when Ball reaches a certain Y, start animation. Then reverse the animation when it is on collision with the ground. Keep the rotation of the ball to 'No' in physics settings.
I know my .capx is very crude, but I hope it gives you some ideas, whether you only program or use animation frames as extra.
- R