Question for guys that are into physics

[grindz]

FYI, here's a good video demonstration of this effect:

HSV B.13 - level cue follow shot hop over stacks of coins
​

Regards,
Dave

-----------------------------------------
Nice clip. You cleared that last stack by about a quarter, a nickel and 7 dollar bills. :smile:
------------------------------------------
>>Actually, the added weight behind the 1-ball makes the CB bounce back some. <<
-----------------------------------------
Isn't it because the force (maybe mass is a better word..or both) that the whole rack exerts greatly outweighs the CB with it's mass and force? And because of the absence (or minimized path) of jumping CB to make that force go vertical instead it goes backward?

I did sleep through a couple of my physics classes (not to mention my grade) so I gladly stand corrected by someone who has studied the subject in depth. I DO find it infinitely intriguing though! Now if we could have held class at the pool hall....................:smile:

td

 

[dr_dave]

break hop physics

Isn't it because the force (maybe mass is a better word..or both) that the whole rack exerts greatly outweighs the CB with it's mass and force? And because of the absence (or minimized path) of jumping CB to make that force go vertical instead it goes backward?

A non-airborne CB has no force pushing it up at impact (assuming the CB has negligible top or bottom spin). It bounces back due to the larger effective mass of the rack.

Regards,
Dave

 

[Patrick Johnson]

To reduce ball hop, try to keep the cue more level (less elevated) at impact.

That's good advice. There's also a way to improve your results even if you can't entirely get rid of "the hops": adjust the length of your break shot so the cue ball is at the bottom of its hop (touching the cloth) when it hits the rack. If you're breaking from the head string, try moving back some. If you're breaking from the head rail, try moving forward some.

pj
chgo

 

[dr_dave]

if you can't beat the hops, move the hops

That's good advice. There's also a way to improve your results even if you can't entirely get rid of "the hops": adjust the length of your break shot so the cue ball is at the bottom of its hop (touching the cloth) when it hits the rack. If you're breaking from the head string, try moving back some. If you're breaking from the head rail, try moving forward some.

Excellent suggestion! This does assume the break speed is fairly consistent so the hops are in the same place every time.

I still like trying to make the hops smaller by keeping the cue more level (less elevated), if possible.

Regards,
Dave

 

[avmaster]

I break trying to keep the hop to a minimum, I strike the CB high center, cue as level as possible (scrapped knuckles more than once on the rail) upon impact the CB comes back 6 to 8 inches then powers through to the back rail. Results in maximum spread of the rack and normally two to three in pocket.

 

[jason]

Level on the Break

It is impossible to break with a "level" cue stick. The height of the rail and the length of the cue stick prevents that. What you can do is reduce the effect by lowering your shoulder and putting english on the ball (while keeping a powerful stroke). There are very few strokes in on the table where you can actually hit the ball level to the playing surface.

With that being said, all balls with enough force will "jump" with a level downward stroke.

 

[Patrick Johnson]

Excellent suggestion! This does assume the break speed is fairly consistent so the hops are in the same place every time.

I still like trying to make the hops smaller by keeping the cue more level (less elevated), if possible.

Me too, especially since it gives you more flexibility to change where you break from when needed. One way to get your stick more level is to try breaking away from the rail. The ideal position for this (all else being equal) is with the ball on the head string and the stick over the corner pocket, which puts maximum distance between the rail obstacle (the back of the pocket) and the cue ball, letting the butt be at its lowest possible position - but watch the knuckles!

Even with the butt as low as possible there's no eliminating the hops completely, so it might still be worthwhile to try different spots and shot lengths to find the optimum "hop length" for your break speed (maybe even to vary the speed slightly).

This game is too easy... maybe I'll take up nucular physics.

pj
chgo

 

[avmaster]

It is impossible to break with a "level" cue stick. The height of the rail and the length of the cue stick prevents that. What you can do is reduce the effect by lowering your shoulder and putting english on the ball (while keeping a powerful stroke). There are very few strokes in on the table where you can actually hit the ball level to the playing surface.

With that being said, all balls with enough force will "jump" with a level downward stroke.

This is true to an extent. I stated " as level as possible". The downward stroke is also true, but I never use a downward stroke. I have found another way as I posted previously. Anyhow, it works for me.