Exploring conservation of momentum with a python model of elastic collisions
Here's what I like to say: "you don't really understand something until you model it."
So, let's do that. Here is a numerical calculation of two colliding balls. With this, we can see what happens to momentum and kinetic energy as the two balls interact in different cases.
Here is the code. You should play with this.
https://trinket.io/glowscript/5d0476f28e