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Shaft
01-22-2007, 07:03 AM
Does anyone know? Does the speed of the moving ball (usually the cue ball) increase or decerease the degree of the throw effect?

Jal
01-22-2007, 10:37 AM
<blockquote><font class="small">Quote Shaft:</font><hr> Does anyone know? Does the speed of the moving ball (usually the cue ball) increase or decerease the degree of the throw effect? <hr /></blockquote>More speed generally means less throw. What's important is the speed of the surface of one ball relative to the surface of the other ball at the point of contact. So while it's generally true that a faster cueball produces less throw, it's not always the case.

Jim

Billy_Bob
01-22-2007, 11:04 AM
Throw test...
http://www.youtube.com/watch?v=D-xtzn4vbiQ

Shaft
01-22-2007, 12:07 PM
Thanks, Billy_Bob. The video helps a lot.

dr_dave
01-22-2007, 01:05 PM
<blockquote><font class="small">Quote Shaft:</font><hr> Does anyone know? Does the speed of the moving ball (usually the cue ball) increase or decerease the degree of the throw effect?<hr /></blockquote>I have two instructional articles that address that question in detail for both collision-induced throw (CIT) and spin-induced throw (SIT). The articles (September '06 (http://www.engr.colostate.edu/~dga/pool/bd_articles/2006/sept06.pdf) and December '06 (http://www.engr.colostate.edu/~dga/pool/bd_articles/2006/dec06.pdf)) have many good illustrations, examples, and video links that help you fully understand all of the effects.

Happy throwing,
Dave

Bob_Jewett
01-22-2007, 06:15 PM
<blockquote><font class="small">Quote Shaft:</font><hr> Does anyone know? Does the speed of the moving ball (usually the cue ball) increase or decerease the degree of the throw effect? <hr /></blockquote>
A plot that shows how speed affects throw in a combination shot is at http://www.sfbilliards.com/throw.gif and the full article about that test is the June 1995 article at http://www.sfbilliards.com/articles/BD_articles.html

This result matches the theory that Dr. Dave explains in his articles about friction. In particular, the theory predicts both the equal throw for nearly full hits and the reduced throw for higher-speed cuts greater than about 30 degrees.

Shaft
01-23-2007, 07:25 AM
Thanks Dr. Dave and Bob. As an engineer geek who actually loved physics, I really appreciate the technical links.