Dear Mr. Hwang,

I have been looking for realistic data from real-world table tennis. These are some facts, that I was wondering if they could be integrated to the model:

- ball diameter: 40 mm
- ball weight: 2,7 g
- coefficient of friction between ball and table: 0,4 to 0,6
- typical ball speed when it reaches the racket: 8 to 12 m/s
- typical ball rotation when it reaches the racket (data here is not too reliable, so I increased the range):  3000 to 9000 rpm 

The newly introduced R*w and Vx-R*w  vectors are very instructive. It would be nice to have them also in the contact point between the ball and the wall.

Best regards.