AzBilliards.com Physics help?
 Page 4 of 4 « First < 234
(#46)
Patrick Johnson
Fish of the Day

Status: Offline
Posts: 20,720
vCash: 1700
Join Date: Jun 2007

07-18-2019, 02:39 PM

Quote:
 Originally Posted by goettlicher Great answers. So if I can move my cue stick at 10mph into contact. How fast in mph does the cue ball leave, assuming a fairly loose grip?
13-15 mph with any grip or none.

pj
chgo

(#47)
vinay
AzB Bronze Member

Status: Offline
Posts: 31
vCash: 500
Join Date: Jan 2019
Location: New York, NY

07-18-2019, 02:42 PM

Quote:
 Originally Posted by goettlicher Great answers. So if I can move my cue stick at 10mph into contact. How fast in mph does the cue ball leave, assuming a fairly loose grip?
Assuming a hard leather tip and an 18oz cue, about 13mph. Maybe about 14mph with a phenolic tip.

It might be possible to verify this with one of those apps that measures break speed along with some careful video analysis to figure out what speed the cue is moving at before impact, or some custom timing hardware I wish I had access to a real high speed camera, but those things are incredibly expensive.

I am actually curious about what's driving your interest here. Just curiosity or something else?

(#48)
dr_dave
Instructional Author

Status: Offline
Posts: 10,131
vCash: 1700
Join Date: Dec 2004

07-18-2019, 02:45 PM

Quote:
 Originally Posted by Patrick Johnson I think Bob and Dave and Mike are saying the soft skin of the hand effectively isolates the cue from your hand/arm during the millisecond of contact.
And any force that the grip hand might be exerting on the cue during contact would be too small to have any meaningful effect anyway compared to the extremely large force between the cue tip and CB. And many (if not most people) are exerting very little force with the grip right before contact anyway since the cue has already reached the desired speed at contact with the ball. That is clear in the acceleration plots in the various resources on the stroke acceleration resource page.

For those interested, here are some other resources that help back up some of these claims:

effects of light vs. tight grip

cue tip contact time

TP B.22 – How peak tip contact force and contact patch size vary with shot speed, and drop tests

There is some good discussion in this thread,
Dave

 (#49) duckie GregH   Status: Offline Posts: 3,697 vCash: 500 iTrader: 0 / 0% Join Date: Oct 2005 Location: Milpitas Ca 07-19-2019, 05:12 AM What’s a firm stroke? What’s a medium stroke? What’s a soft stroke? This is a major issue for a lot of your test scenario..... Subjectivity on stroke speed. Not everyone will have the same opinion on what those speeds actually are. Plus, why use a mph scale on the graph? In pool, we don’t deal in miles or hours, but in inches and seconds. Why not use inches per second? Plus......does anyone know what range of speeds they stroke at? How can you gage if you are stroking at 1 mph or rather 17.6 inches per second. I play a lot of 14.1, which requires a lot of slow rolling the balls. My firm stroke in playing 14.1 might be considered medium stroke for others playing 8 ball. Last edited by duckie; 07-19-2019 at 05:17 AM.
(#50)
logical
sarcasm while you wait

Status: Offline
Posts: 1,288
vCash: 1700
Join Date: Jul 2013
Location: Northern fringe of the Motor City suburbs

07-19-2019, 06:12 AM

Quote:
 Originally Posted by duckie What’s a firm stroke? What’s a medium stroke? What’s a soft stroke? This is a major issue for a lot of your test scenario..... Subjectivity on stroke speed. Not everyone will have the same opinion on what those speeds actually are. Plus, why use a mph scale on the graph? In pool, we don’t deal in miles or hours, but in inches and seconds. Why not use inches per second? Plus......does anyone know what range of speeds they stroke at? How can you gage if you are stroking at 1 mph or rather 17.6 inches per second. I play a lot of 14.1, which requires a lot of slow rolling the balls. My firm stroke in playing 14.1 might be considered medium stroke for others playing 8 ball.
Feel free to post your research results.

Sent from my SM-G950U using Tapatalk

 (#51) goettlicher AzB Silver Member     Status: Offline Posts: 367 vCash: 500 iTrader: 0 / 0% Join Date: May 2006 07-19-2019, 06:19 AM Vinay: I was presented with this question in Pool School this weekend. I was not prepared to give them an answer. I needed to know the real truth of the matter. Now I am better armed because of this discussion board.
 Page 4 of 4 « First < 234

 Thread Tools Rate This Thread Rate This Thread: 5 : Excellent 4 : Good 3 : Average 2 : Bad 1 : Terrible

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Main Category     Main Forum     Live Stream Area     Wanted/For Sale         For Sale Items         eBay Auctions         Wanted     Room Owner Discussion     14.1 Pool     Canadian Pool     Snooker     Carom Billiards     Memories of Steve Mizerak     English Pool     Billiard and Pool History in the U.S.     BEF Juniors Pool     Non Pool Related     Test Area     Cuesports: Rules & Strategies     AzB Hall of Fame     Pool Room Reviews Tournament Talk     U.S. Tournament Announcements     European Tournament Annoucements     Asian Tournament Announcements     Super Billiards Expo     Junior National 9-Ball Championships     World Championships     US Open Championships     Derby City Classic/Southern Classic     BCA Pool League World Championships     US Bar Table Championship     WPBA     Matchroom Events     Eurotour     Other Tours & Events Products Talk     Pool Tables and Accessories Reviews     Cue Reviews     Cue and shaft reviews     Cue Case Reviews     Cue Machinery and Supplies     Cue & Case Gallery     Ask The Cuemaker     Cue Accessory reviews     Other Item reviews     Talk To A Mechanic Instruction & Ask the pros     Aiming Conversation     George 'Ginky' San Souci     Instructional Material reviews     Instructor Reviews     Melissa Morris     Sarah Rousey     Ask The Instructor