Hello all, Need to resolve an argument with a friend! without complicated math and physics, could we say OB hit at very soft speed throws due to friction between OB & CB, and at STUN shots OB throws & spins because the CB and OB get deformed so very slightly at contact point and stick and drag each other? I know they are made of hard material, but still could deform at stun say .000 something? what do you think. Thanks
why stun and soft speed shots throw OB ?
- Thread starter naji
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Uncomplicated physics:
The slower the relative motion (cueball surface to object ball surface), the higher the friction coefficient. In a stun shot, the cueball isn't spinning so it's relative motion is simply its speed; in a slow shot... welll, it's slower.
Thanks for quick reply, I agree at slow speed. One can argue at very high stun speed OB does not throw as much as at slower but fast stun speed, of which made your argument about relative speed not convincing!
Thanks for quick reply, I agree at slow speed. One can argue at very high stun speed OB does not throw as much as at slower but fast stun speed, of which made your argument about relative speed not convincing!
takeitdown
Banned
Really its like the edges of ball are gears. CB spins clockwise engages OB and like gears spins it the opposite way. The dirtier the balls or the longer they are in contact, the greater the effect. The balls are not distorted.
It's all relative.
Slow stun speed has more throw than fast stun speed.
Fast stun speed might have more throw than slow speed where the cueball is rolling and not sliding.
Slow speed where the cueball is rolling has less throw than fast speed when the cueball is rolling.
I'm not arguing, nor trying to convince. I'm trying to explain without complicated physics, as that is what you asked.
I'm not disputing slow stun shots throw more but the coefficient of friction, of the CB and OB, is a constant.
It doesn't have to be. If the coefficient of friction doesn't agree with the empirical data, then it can be changed.
That's why in high school physics they teach the coefficient of static friction and the coefficient of kinetic friction for the same two surfaces.
They are not constant. The CoF changes wrt relative velocity of the surfaces.
Fred would know he's an egineer type person thing guy. It's probably why a very slow extreme english shot (I mean if you shoot like you are in slow motion) would kick the cueball to the side and a normal stroke english shot would send it forward.
FYI, all of your questions, and many more, are answered in the articles and videos here:
maximum throw resource page
The coefficient of friction (COF) between the balls varies significantly with relative surface speed between the balls. For more info, see: "Throw - Part II: results" (BD, September, 2006).
Throw is largest with stun because all of the friction force is pushing sideways (in the throw direction). With top or bottom spin, the friction force between the balls is not horizontal, so you don't get the full throw effect. For more info, see the follow/draw throw effects resource page.
For explanations and demonstrations of all throw effects, see items 16-37 in the list under the videos on the squirt, swerve, and throw effects resource page.
Enjoy,
Dave
Thanks much Dr. Dave and all