Snooker becomes the latest sport to head to Saudi Arabia this week and with it comes a new twist – the golden ball. The 23rd ball will make its debut at the World Masters of Snooker in Riyadh ...

A red snooker ball and a blue snooker ball (each with a mass of 160 g) collide. The red ball is travelling from left to right at 0.28 ms-1. The blue ball is travelling from right to left at 0.12 ms-1.