1.6. Spin Speed and Swing Speed
Now let's see how the ball moves when it hits the rotating ball by moving the racket perpendicular to the direction of travel.
The figure below is a view seen from above.
I wonder how will the ball actually moves?
To the readers, I want you to read on the assumption that you hit a side-spinning ball by your own racket.
Maybe, it moves unlike your expectations.
1.6.1. Blocking the side spin of ball by a stopped racket
When the ball on side-spinnig at the flight speed Vx and the spin Vω is striked to the resting racket, which spin will convert to a flying due to the friction of rubber, and return at the flight speed-Vy and -Vω.
1.6.2. The swing in the spin direction of the ball
Moving the rakcet slow
Moving the rakcet fast
Comparing using the relative speed, if the spin speed is faster than the racket sliding speed, the difference of the speeds will shift the ball to the horizontal direction and reduce the spin speed to the racket sliding one. The spin speed will slow down to the racket sliding speed.
If the spin speed is slower than the racket slide speed.
The spin speed will be accelerated until the slide speed and return without shifting laterally.
1.6.3. The swing in the opposite spin direction of the ball
Moving the racket slow
Moving the racket fast
Comparing using only speed size, if the spin speed is faster than the racket sliding speed, due to the friction of rubber the difference of the speeds will have the flight direction sift to the horizontal and reduce the spin speed to the racket sliding one.
if the spin speed is slower than the racket sliding speed,
the spin speed will be deaccelerated untill the difference of the speeds, the ball will be returned without shifting laterally.
1.6.4. Why does it become so?
Why it become like that. I want explanations more essential. Don't you?
For such a person, I summarized as Section 1.11. Relational Expression between Ball and Swing Speed", so please refer to that.