Cueball Physics - The Force of the Cueball

mikepage · Aug 13, 2019

MitchAlsup said:
Ignoring air resistance;

Yes.

The forward rolling CB still has friction while rolling on the cloth--just a lot less than before it accumulated natural forward roll.

Before it achieves natural roll there is a real friction force on the cueball. Once it achieves natural roll, there is no more friction force. There is a "rolling resistance," where the cueball slows down because it is constantly trying to climb out of its own divet. If we squint, we can think of this as like a friction force. But it is actually different and kind of irrelevant here.

My only complaint was the misuse of the word "force" in conjunction with the physical explanation. Physics has a strict definition of what a "force" is.

And I think he is using it appropriately. If there is anything nonstandard, it is that he refers to it as the "force OF the cueball," rather than the "force ON the cueball."

And while the video was both entertaining and well executed, nicely demonstrating the effects. The word "force" is inappropriate in a physics context.

.

Once again all the acceleration of the cueball he refers to--speeding up, slowing down, and turning--is a direct result of the force he discusses. The physics is fine.

Ralph Kramden · Aug 13, 2019

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MitchAlsup said:
.
Ignoring air resistance;

The forward rolling CB still has friction while rolling on the cloth--just a lot less than before it accumulated natural forward roll.

My only complaint was the misuse of the word "force" in conjunction with the physical explanation. Physics has a strict definition of what a "force" is.

And while the video was both entertaining and well executed, nicely demonstrating the effects. The word "force" is inappropriate in a physics context.

Sorry.. but I do like the word FORCE.
As for anyone ignoring air resistance.

Jack Nicklaus was once asked why he always tees the ball so high?
He replied that air resistance was so much less than dirt resistance.

May the FORCE be with you...

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pwd72s · Aug 13, 2019

Sharivari said:
Thank you guys. Great to hear that all the work I put in is appreciated

very much appreciated...thank you! :thumbup:

MitchAlsup · Aug 13, 2019

mikepage said:
Before it achieves natural roll there is a real friction force on the cueball. Once it achieves natural roll, there is no more friction force. There is a "rolling resistance," where the cueball slows down because it is constantly trying to climb out of its own divet.

That "rolling resistance" is friction of the CB compressing the cloth as it rolls over.
{Plus that completely negligible air resistance.}

Bob Jewett · Aug 13, 2019

MitchAlsup said:
That "rolling resistance" is friction of the CB compressing the cloth as it rolls over.
{Plus that completely negligible air resistance.}

Well, Wikipedia has this to say about rolling stuff:

"Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement) of the wheel, roadbed, etc. is recovered when the pressure is removed. Two forms of this are hysteresis losses (see below), and permanent (plastic) deformation of the object or the surface (e.g. soil). Another cause of rolling resistance lies in the slippage between the wheel and the surface, which dissipates energy. Note that only the last of these effects involves friction, therefore the name "rolling friction" is to an extent a misnomer."

I think this looks reasonable and correct.

dr_dave · Aug 13, 2019

Sharivari said:
Hi AZB,

I just released a video that took me over 40 hours to produce. And because thats a lot of time for a just 12 minute long video I want to share it with as many players as possible.

And of course I want to know what you think of it, how I can improve my videos in general and what I am most interested in. Did you learn something new? I am asking because I don't only want to produce videos that are helpful for beginners, but also for experienced players.

So if you're interested in the cueball behaviour you should give this one a try
https://youtu.be/KL0W45AkNMo

Sharivari

Excellent work as always.

Keep up the good work,
Dave

Cueball Physics - The Force of the Cueball

mikepage

AzB Silver Member

Ralph Kramden

BOOM!.. ZOOM!.. MOON!

pwd72s

recreational banger

MitchAlsup

AzB Silver Member

Bob Jewett

AZB Osmium Member

dr_dave

Instructional Author