I want to play!
If you have two identical balls with one exception, one has the lowest rg allowed and one has the highest rg allowed. Both balls are drilled with the same layout and the pin is 3 3/8 from the PAP. Both balls have enough differential to flare at least 4 inches.

If a bowler throws the high rg ball with 350 revs off his hand and then throws the low rg ball the exact same way, will his rev rate increase to even 351 revs with the low rg ball?

Ron Clifton
Looking for perspective

My thoughts are this.  If you have two identical balls with the same exact pin placement, the RG will be the same.

  The high RG reading and the low RG reading of any given ball are predicated on where the pin ends up after drilling.  If both balls were drilled with the pin 3 3/8 inches from the pap, both balls will have the same RG.

  The only way that comes to mind to get a higher AND lower reading from the same ball is to move the pin either towards the track or towards the pap.

  Now, you could take two balls with identical COVERSTOCKS in identical preps and install different weightblocks in them to achieve this, but not with totally exact duplicate balls with duplicate weightblocks.

  Now, if in theory you COULD do this experiment, their would have to be some type of formula to allow for the calculation of force exerted upon the ball divided by the force needed to impart spin on the ball.  It would probably have to include a variable for allowance of the fact that you would have to allow for the minute difference between spin properties of a high RG object vs a low RG object, ie.. how much difference it takes to get them started in the first place and how much force is left after you get them started  and how much total force is available in the beginning.  

  I believe JohnP has a point, except that, at the point that the skid stops and the roll starts, doesn't then the RPM's become a function strictly of the balls initial velocity?  I mean, if the sliding is done, and the ball is now rolling, doesn't it roll at the speed at which it is traveling down the lane?

  If it is rolling, it can't be skidding, but, if it is turning faster than it is moving, it has to be skidding, even if only slightly, doesn't it?

  If so, then it doesn't necessarily have to pick up RPM's after it picks up its roll, it could also LOSE them, couldn't it, depending on the initial trajectory speed ( velocity)?
--------------------
What did you expect, something PROFOUND?

Good transactions list in my profile


My Bowl.com member page



Edited on 4/12/2008 12:59 PM

Ron, I think you might want to change the criteria a bit, with all things are equal, the only difference between the 2 balls are 1 with higher RG after drill and 1 with lower RG after drill.
--------------------
Laufaye

It will require more energy, more torque to apply 350 revs to the high-RG ball compared to the low-RG ball.  How much more, I don't know.  You can probably figure that out without too much difficulty.  So "same release" is a kind of vague term that would require more thought.

For the same energy (work), because the RG changes, the force you are generating changes, and so the speed at which you can move your fingers, and hence the ball, changes; you are acting on the effective mass (what the RG measures) of the ball at different distances (2.43" vs 2.8"), which will change the torque you are applying, which changes the amount of force you are generating, which changes the speed at which the same energy will move your fingers.

Is it linear?  A 15% increase in the RG gives a 15% reduction in revs?  Probably not.  Do your muscles respond to the additional workload demanded of them in a linear fashion to exactly counteract that?  Doubt it.

The basic point is that there are entirely too many forces and systems interacting within and around your body to say for certain.  Considering a simple physical system that solely includes the ball and some "ideal" fingers, it requires more energy to put 350 revs on a high-RG ball than a low-RG ball.

SH