[Tom Line]

I believe the proper way to do your ball flight calculations is using energy.

Potential energy of a spring is converted into kinetic energ of the ball. As someone stated, though, you are going to lose engery due to the inelasticness of the collision.

A good first-cut way to measure that is to take the ball from a height. Say 8 feet. Drop it on concrete and measure the height it rebounds. Say 4 feet.

Therefore, in a collision the ball will lose around 50% of the input energy just to inelastic deformation.

Then you can take the potential energy of your system, multiply it by your percentage, then use your new energy and the kinetic energy formulas to calculate the imparted velocity. Then you can use the simple projectile formulas and determine how far it will go.