On a flat earth or a spherical one?
Pool Ball Terminal Velocity
- Thread starter Mr. Bond
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On a flat earth or a spherical one?
Approximately 30 feet and a fall of 1.4 seconds will get you to about 30 mph.
Getting a frozen rack standing on end to have it hit the lead ball is left as an exercise to the student.
There's a good argument somewhere in there to refute Max Eberle's theory....
...but I'll leave it to more educated minds to pursue that.
..'course, he might not believe in gravity, either.
About 1.5 second drop, goes about 35 ft.
Near and dear to my heart. For a flat earth, if you're near the edges, balls would "drop" sideways-ish. As with the waterfalls .
And of course, with a flat earth, we'll throw out the earth gravitational constant since it wouldn't be constant on a flat earth model.
Freddie <~~~but I'm ignorant of such things
lots of good stuff--and not so good stuff--aside, this may help.
The speed in mph is pretty close to 5.5 * square root(height in feet). So, for example from a height of 16 feet, it is 5.5*4, or 22 mph. This is a pretty fast break.
Here is a graph that shows the bigger picture.
Dropping from higher heights than shown here, the speed will start dropping off below this no-air prediction. But in this height range it is probably OK.
I don't know why you are asking, but if you have visions of building a cueball ramp to get consistent and predictable cueball speeds to model a break, then you will have to deal with fact your falling cueball might pick up a lot of forward spin as it goes from down to sideways. That is, a cueball in an actual break has in general relatively little spin for its high speed. The falling cueball may not.
Attachments
Just for anyone interested, I used the Break App for several breaks at the US Open 8-ball.
Fastest break I clocked was Thorsten at 25mph. Shane was mostly at 23-24mph. Dennis was around 22-23 (never hit 24), and Alex was consistently at 21.5ish.
Freddie <~~~ 20ish
Fastest break I clocked was Thorsten at 25mph. Shane was mostly at 23-24mph. Dennis was around 22-23 (never hit 24), and Alex was consistently at 21.5ish.
Freddie <~~~ 20ish
One of my favorite books of all time is called "The Character of Physical Law" and it is transcripts from lectures Feynman gave in 1964. The first chapter addresses essentially your question
http://people.virginia.edu/~ecd3m/1110/Fall2014/The_Character_of_Physical_Law.pdf
Cool book .. read the first chapter and will read the rest later.
Here is a quote from the first chapter, page 14 -- "I have chosen for my special example of physical law the theory of gravitation, the phenomena of gravity."
So, the author confirms here that the gravity concept is in fact a theory, not scientific fact. He even refers to gravity as a "phenomena."
I do not know why he refers to this theory as a physical law .. not even sure what that means .. how can it be any kind of law if the force in question can not be defined?
He goes on to talk about the effects of this mysterious force on other matter, but in no way describes what gravity actually is.
I appreciate the link and look forward to reading the rest of the book, however the first chapter only confirms the existence of a force we call gravity, it in no way explains what gravity actually is.
Interesting you should say that.
This was all meant to be a theoretical discussion but I have indeed considered such a ramp before.
Actually, as you pointed out, it would have to be more of a "slide" than a ramp, but still not impossible to do.
Well, not if you actually believe, the Flat Earth society (yes, there is one) says that gravity is a side effect of the earth accelerating upward:
https://wiki.tfes.org/Universal_Acceleration
You can't make this stuff up... well, I couldn't make it up.
Though... how about hollow earth? Ever figure out that one? If earth was a (say) 10 mile deep shell (assume spherical), and the inside was hollow (and it was somehow strong enough to exist in that form), how does gravity work on the inside shell? Do people stick to it upside down?
What's the terminal velocity of a pool ball dropped from 5 feet below (i.e. closer to the center) the shell? Assume normal atmosphere. How about dropped from the center of the shell?
No, it's a democratically decided concept. You vote for it.
What happens is people line up at the top of a cliff. Those who think gravity does not exist are invited to step off and prove it.
This happened millennia ago; all those who voted for it to exist are our ancestors.
Though it may be time for a new election.
Well, not if you actually believe, the Flat Earth society (yes, there is one) says that gravity is a side effect of the earth accelerating upward:
https://wiki.tfes.org/Universal_Acceleration
You can't make this stuff up... well, I couldn't make it up.
Though... how about hollow earth? Ever figure out that one? If earth was a (say) 10 mile deep shell (assume spherical), and the inside was hollow (and it was somehow strong enough to exist in that form), how does gravity work on the inside shell? Do people stick to it upside down?
What's the terminal velocity of a pool ball dropped from 5 feet below (i.e. closer to the center) the shell? Assume normal atmosphere. How about dropped from the center of the shell?
No, it's a democratically decided concept. You vote for it.
What happens is people line up at the top of a cliff. Those who think gravity does not exist are invited to step off and prove it.
This happened millennia ago; all those who voted for it to exist are our ancestors.
Though it may be time for a new election.
Actually you are describing the effects of the force called gravity when you illustrate people jumping off a cliff -- lol -- You have not defined in any way what that force actually is.
Thanks for the laugh !!
That's OK. I also haven't defined what "I" am, and how "I" know I exist, so knowing how "I" am held down to the earth is the least of my worries.
Prove you exist, and are not a figment of my imagination, and I'll define gravity for you.
Imaginary friends in the sky who tell you to kill each other over varying interpretations of a book written by hundreds of people and rewritten over 2000 years by thousands more *might* be a theory. It might be homicidal aliens too. No one actually knows. Therein is the difference between faith and science.
Further explained:
Gravity is observable, every single time. It is the attraction of two bodies, the force of which decreases (in two bodies with same mass in each experiment) as an inverse square of the distance between their centers. It can be observed, very easily, with two boats in close proximity in a harbor: leave them untied and they will drift together. The more massive the ships, the more quickly it will occur. Every object exerts gravity on every other object. The reason you jump and the Earth doesn't move up (it does, but not a measurable scale) to meet you is a function of the difference in mass.
None of this has anything to do with the OPs question though, to which I might ask, why do you want to know? Are you planning to drop a pool ball from an elevated structure onto the head of a Ram-Shot user? If so, don't leave fingerprints. Also, just video it and Bob or Freddie can discern the exact figures from there.
Immanuel Velikovsky felt that gravity was an electromagnetic phenomenon.
He upset many experts in a few fields and was ostracized by many of his peers....
....but when Albert Einstein died, an opened book by Velikovsky was found on his desk.
...so some great minds did not find him irrelevant.
He upset many experts in a few fields and was ostracized by many of his peers....
....but when Albert Einstein died, an opened book by Velikovsky was found on his desk.
...so some great minds did not find him irrelevant.
This is one of the few scientific type threads to appear on AZB -- your statement is so non-scientific that I am not able to respond to it.
You can 'believe' anything that makes you feel good or better about yourself and your environment .. everything is going to be alright .. ;-)
By the way .. you do not have to worry about proving anything to me.
Have a nice day.
I understand and agree with what you wrote here. But again, this is only describing the effects of gravity and not identifying what it actually is.
Why not just say that an object of greater density than it's surrounding environment will fall simply because it is heavier?
I would hope we could all agree that is a scientific fact ... and quite simple.
Did you know that Newton's gravity concept has been modified by different scientists as new discoveries made the original theory invalid? I remember that Albert Einstein was one of them.
Why do I want to know? Because I am always attempting to have a greater understanding of reality and the physical world that we live in. Simply seeking facts and the truth, not all that interested in theory's being used as a building block to ratify further scientific fact.
I am an open minded individual. If anyone can define what gravity actually is in scientific terms, I would be the first to thank him, as he would greatly further my knowledge and understanding.
Can't find a LIKE button, so.......:grin-square: