Bounce of the cue ball in snooker

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The discussion centers on the phenomenon of the cue ball bouncing off snooker cushions at high speeds, with some observers claiming it can rebound faster than it approached. This effect may be influenced by the spin applied to the ball, which can convert rotational kinetic energy into linear kinetic energy. Participants note that the trained eye often expects a reduction in speed upon impact, leading to the illusion of increased speed when this expectation is not met. There is a call for further analysis of the ball's speed before and after cushion impact, as well as a lack of standardized coefficients for billiard cushion restitution. Understanding the physics behind these interactions is crucial for deeper insights into cue ball dynamics.
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I was watching a game of snooker, and sometimes the cue ball bounces off the cushions with surprisingly high speed. Some people often say that it comes off the cushion faster than it went into it. And I started thinking - is that even possible? Does physics work that way?
 
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Maybe if it has spin
 
tkyoung75 said:
Maybe if it has spin
Yes top spin giving angular momentum which will not be apparent from a normal view point. You can see a slowed down cue ball with spots more easily like in this video.

 
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TSN79 said:
is that even possible? Does physics work that way?
Have you ever played with a "superball" (high friction bouncy rubber ball)? If you give them lots of spin, they shoot off very fast at bounce. Rotational kinetic energy is converted into linear kinetic energy.
 
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TSN79 said:
I was watching a game of snooker, and sometimes the cue ball bounces off the cushions with surprisingly high speed. Some people often say that it comes off the cushion faster than it went into it. And I started thinking - is that even possible? Does physics work that way?
I think the effect is that the trained eye expects a certain reduction in speed upon impact with the cushion. When this doesn't happen and the ball rebounds faster than expected it creates the illusion that it speeded up.

That said, I would like to see some analysis of the speed of a ball before and after it strikes the cushion.

The cases in question are not where spin is involved. Those cases are known and understood.
 
PeroK said:
I think the effect is that the trained eye expects a certain reduction in speed upon impact with the cushion. When this doesn't happen and the ball rebounds faster than expected it creates the illusion that it speeded up.

That said, I would like to see some analysis of the speed of a ball before and after it strikes the cushion.

The cases in question are not where spin is involved. Those cases are known and understood.

Will the spin not be transferred to the cushion once it strikes?
Intuitively I would thought the energy is transferred to a small point on the rubber cushion which recoils then springs back pushing the cue ball out again.
This is from playing the game (pool not snooker) and trying to adopt some physics I understand (to some extent)
Also, I found this study from Loughborough university – it made sense then got tricky edit not impossible
https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/15087/3/Ball%20behaviour%20under%20under%20cushion%20impacts.pdf
Let me know what you think and an idiots guide would be appreciated.
 
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I could not find a standard coefficient of restitution for billiard cushions, although the above reference indicates what one might expect. The cushions are made of rubber (natural or synthetic), and accuracy of bounce over a range of speeds is a key performance measure.
 
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