#
The Motion of a Billiard Ball

*A video walkthrough of the example page is available online here (Password: SELFORGA22!).*
**Abstract.** We very deeply study the intricate motion of
round and coloured billiard balls on a table using a very nice simulation
written in D3.js.

### Theory

In this completely useless simulation project, the motion of a reflected
ball is shown. This is similar to billiard, a fun game shown below.

The ball has a radius of $r = \mathcal{R}$. We describe its dynamics by
a vector
\[
\vec{v} = (x, y, dx, dy)^T,
\]
where $x$ and $y$ are the center coordinates of the ball and $dx$ and
$dy$ describe the direction the ball is moving in.