Parimal Prasoon Software Developer

Trajectory-of-a-billiard-ball

I am taking a computational physics course this semester, and one of my assignment was to plot the trajectory of a billiard ball and use Euler’s method to solve it. Here's a simple guide for it. I used MATLAB ( you can view my post on how to install MATLAB on Ubuntu [here](http://parimal.codes/Setting-up-MATLAB-on-Ubuntu/)) for the assignment. Assumptions – - Table is friction less. - All collisions are elastic. - The table is a square. with origin being the centre of the table. ![](/media/editor/screenshot-from-2019-02-23-14-27-48_20200206215326050410.png) Whenever the ball strikes either x = 4 or x = -4, its velocity in the x direction is reversed and velocity in y direction remains same. Similarly, if the ball strikes y = 4 or y = -4, its velocity in the y direction is reversed and the velocity in x direction remains same. These will be the boundary condition for our code. The initial conditions are from the assignment problem. ![](/media/editor/screenshot-from-2019-02-23-14-34-09_20200206215359022794.png) ![](/media/editor/screenshot-from-2019-02-23-14-31-34_20200206215416845397.png) That’s it basically. Nothing impressive, but I was getting bored so decided to blog it down anyway.