Re: Need Clarification on Throw/APAPP


Bob Jewett wrote:
> Jal <jal@xxxxxxxxxxxxxxx> wrote:
> ...
> > If you or anyone could provide the cueball's speed, spin?,
> > cut angle and throw from Marlow or from your own data,
> > it would be nice.
>
> I looked at the section in Marlow this morning. He used more or
> less the same setup I did in the previously mentioned article and
> plot plot of throw vs. cut angle and speed. I think he used a
> 45-degree incidence of the cue ball on the two frozen balls. He
> had previously calibrated his arm for 0.1, 1.0 and 10 meters per
> second. I would have thought that a 10:1 variation in mu would
> result in a 10:1 variation in throw angle, given a 45-degree
> angle of incidence.

Thanks for looking that up. It appears then that Dr. Dave
used the cueball speeds you just quoted for the surface speeds
in his derivation of the constants. I wouldn't know why he
didn't multiply them by sin(45) to get the surface speeds.

And yes, I would expect the 10:1 variation too, but in
Dr. Dave's paper he just quotes the mu values, so as far as
I can tell there is no problem there. Perhaps I'll query
him on these issues.

I tried to download your articles but gave up after 7 MB and
a dozen restarts. I can wait till you separate them at some
time in the future.

Thanks again.

Jim

.

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