Just like to re-ask the question from NOBLE DISK Volume 2 Issue 1
A few years ago, a friend found an article about yo-yos in an old magazine, photocopied it, and gave me a copy.
I have since misplaced the article, but I do remember that it included a nice short history of the yo-yo. Also, I remember that the first paragraph had a line to the effect that an expert yo-yo thrower could make the yo-yo spin at 8,000 RPM.
The term expert was never defined, but I would figure that the measurement was taken just after the expert threw his best sleeper, and I would figure that the longer the sleeper, the more RPMs would be needed to attain the longer sleep time.
8K is indeed impressive. That is redline for a sports-car engine.
I wonder if I could make my yo-yo go 8K. I consider myself to be an expert, or at least I can do a ten second sleep. Is a ten second sleeper 8K? Also, one would have to take into account that the less friction involved the less RPMs one would have to devote to the ten second sleep. And it’s corollary: The length of the sleep does not determine the number of RPMs. For each yo-yo, the amount of sleep for a throw of any given speed would vary.
At any rate, the expert yo-yo thrower would have put as many RPMs as possible into his best sleeper, and it is only the number of RPMs at the point in time immediately after the sleeper is thrown that we are interested in.
What type of yo-yo was this measurement taken with, how was the measurement taken, who threw it, and how long was the sleep?
I throw a Tom Kuhn No Jive yo-yo, and can throw a ten second sleeper on demand. Do I throw an eight thousand RPM sleeper?
One could spend a great deal of effort doing appropriate research to the above questions, rotational velocity, total mass and average speed of that mass, the total amount of energy in the system, etc. I don’t have the time or equipment necessary.
Still though I did deem it worth some effort. And to this end I did a bit of math.
A Tom Kuhn yo-yo is 2 3/8 (2.375) inches across as it comes from the factory.
2.375 x 3.141 = 7.4575 inches diameter
7.4575 x 8,000 = 59,660 inches per minute
59,660 x 60 = 3,576,900 inches per hour
3,576,900 / 12 = 298,300 feet per hour
298,300 / 5280 = 56.496 miles per hourThis is 94% of a mile per minute. The inverse of .94 is 106.
Therefore, a Tom Kuhn yo-yo going 8480 RPMs (8000 X 1.06) would be traveling a full mile per minute at its outer edge.
I would very much like to be able to proudly boast that I could make my yo-yo go a mile a minute. How long of a sleeper does one need to do to truthfully make such a boast? Anyone care to devote a bit more effort to this question?
If you have the equipment to do such tests, and the time to devote to such a project, you would surely get your name in print. Sorry: I can’t promise you much more for your effort
Only with a modern twist. Instead of a No Jive, what would be the RPM of a, say, Shutter? More science!
