Inspired by the Washington post contagion simulation of Covid19 (https://www.washingtonpost.com/graphics/2020/world/corona-simulator/) and based on the code: Elastic collisions with Gravity by Jake Vanderplas.
The code is written in Python 3.7.4 using libraries: Matplotlib 3.1.3, Numpy 1.18.1, and Scipy 1.4.1