As title , there has 2 balls(A and B) which I can change Quality 、Radius and Position for two dimensions(x and y axis),

A has a velocity and B quiescence , let A strike to B .

As shown below

I did a sample ,but i can't make it accurately .

test.mw

I want to let my sample like the below sample

http://www.mapleprimes.com/questions/202467-How-Does-Maple-Make-A-Rutherford-Scattering-