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A circulating fan- is the tip of the fan blade moving faster than parts of the blade which are closer to the rotation axis?
August 07, 2026, 05:30 PM
DrDanA circulating fan- is the tip of the fan blade moving faster than parts of the blade which are closer to the rotation axis?
quote:
Originally posted by parabellum:
I reject this reality and divide by zero.
That's ok, since reality is also zero. Therefore, you have the indeterminate form of 0/0 and one must apply L'Hospital's Rule to find out that none of it matters anyway.
This space intentionally left blank. August 07, 2026, 05:34 PM
dsietsquote:
Originally posted by fritz:
For those who grew up in a simpler time, consider the playground merry-go-round. Stand inside the platform and one could hang on for a long time.
The trick was hanging on to the outer bars, and then having the guts to let your feet go ever further out -- until maybe your feet were pulled off the ground. Of course this was loads of fun to watch when the big kids were pushing the merry-go-round as fast as they could, and the little kids were getting flung off into the gravel playground surface. Ah, those were the days.
Our playground had one like this. If you were near the center, pushing at a good walk, the kids on the outside had to really hang on.
August 07, 2026, 05:46 PM
yaniciWaffles are better than pancakes.
John
“You know—everything happens for a reason. But sometimes the reason is…you’re stupid and you made a bad decision.”
Senator John Kennedy, Louisiana
August 07, 2026, 05:52 PM
KeystonerEasiest way for me to visualize this when I took physics in HS, imagine a line of ice skaters holding hands and going in a circle. The skaters closer to the hub have to skate slower. The skaters at the outside radius of the turn have to skate the fastest. Further out from the hub,the faster you have to skate.
The danger of baobabs is so little recognized. August 07, 2026, 06:08 PM
slosigquote:
Originally posted by 229DAK:
This is why some helicopter's main rotor blades have angled/swept tips. As the angular speed increases, the tangential velocity at the blade tip approaches Mach 1, lift is reduced (drag increased), increasing power requirements, it causes degraded efficiency and can cause unwanted vibration. It also increases noise.
Good example:
Republic XF-84H Thunderscreech
This also plays a part in a helicopter’s top speed. As the helicopter moves forward, the rotor blade on one side is advancing while the other retreating (relative to direction of travel). With enough forward speed, the retreating blade isn’t able to make sufficient lift and the helicopter rolls toward the retreating blade.
August 07, 2026, 06:22 PM
HRK
August 07, 2026, 08:31 PM
pbslingerquote:
Originally posted by Keystoner:
Easiest way for me to visualize this when I took physics in HS, imagine a line of ice skaters holding hands and going in a circle. The skaters closer to the hub have to skate slower. The skaters at the outside radius of the turn have to skate the fastest. Further out from the hub,the faster you have to skate.
OK if in this imagination game the skaters are naked girls? The direction and magnitude of breast heaving is taxing my abilities to imagine. Getting a little light headed.
August 07, 2026, 08:35 PM
adorI tried to read everything. Now my head is spinning. This is too deep for me.

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August 07, 2026, 08:43 PM
parabellumBlack magic. Ya got one blade- all one piece, ya see- and different parts of it are going different speeds. Does it disintegrate, fly apart? No.
The work of Satan.
August 07, 2026, 09:42 PM
RightwireThis is why the windmills that generate electrical power are so dangerous to birds. It appears the blades are turning slowly but the last 1/3 of the blade is moving incredibly fast, so much so that the birds cannot visually compensate and usually disappear in a cloud of feathers.
Think about the old merry go-round at the local playground. Stand near the middle and have your friends get it moving as fast as they can. As long as you stay there, you're ok (little dizzy but ok). Walk towards the edge and eventually you get thrown off (big laughs).
1970's Playground Magic.... also the work of Satan

Pronoun: His Royal Highness and benevolent Majesty of all he surveys
343 - Never Forget
Its better to be Pavlov's dog than Schrodinger's cat
There are three types of mistakes; Those you learn from, those you suffer from, and those you don't survive. August 07, 2026, 10:17 PM
tsmccullquote:
Originally posted by PeteF:
Really want your mind blown? While you are standing on the surface of the earth your velocity due to the earths rotation is > 1000 mph.
Only at or near the equator. Standing (or sitting) close to the poles, even a nearly frozen ant beside you could walk orders of magnitude faster than you’re moving!
August 07, 2026, 10:25 PM
1s1kIf you look at those huge commercial wind turbines they look like they are barely moving yet the tip speed is over 200mph.
“While the center hub rotates slowly at 10 to 20 RPM, the extreme length of the blades means the outer tips can reach top speeds of 150 to 230 mph.”
August 08, 2026, 12:10 AM
Southern RebelAll of the above is just an aberration caused by insistence in the mathematical world that pi are squared. If you allow for the potentiality that pi may also exist as a round entity, all of the above becomes just an alternate reality in a parallel universe.
(My son-in-law says problems of this nature are caused because some idiot started using letters mixed in with numerals to do math problems and disrupted the mathematical logic. He and Jethro Bodine are on the same level when it comes to application of the principles of basic mathematical"goesintas".....)
August 08, 2026, 07:07 AM
vthokyquote:
Originally posted by Southern Rebel:
All of the above is just an aberration caused by insistence in the mathematical world that pi are squared.
Pie are round; cornbread are [sometimes] square.
Politicians seem to have forgotten that they work for us, not the other way around.
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God bless America. August 08, 2026, 09:05 AM
V-Tailquote:
Originally posted by vthoky:
Pie are round; cornbread are [sometimes] square.
My cornbread are round.
הרחפת שלי מלאה בצלופחים August 09, 2026, 01:46 AM
lechiffrequote:
Originally posted by BigSwede:
I like pancakes
When the pancake is flipped are the left and right sides traveling faster than the center line of the spatula? and does the answer also hold true of said spatula?
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August 09, 2026, 02:10 AM
OgieGin and Tonic. Reading this thread. Now I have a headache.
August 09, 2026, 05:58 AM
Patriotquote:
Originally posted by parabellum:
Black magic. Ya got one blade- all one piece, ya see- and different parts of it are going different speeds. Does it disintegrate, fly apart? No.
The work of Satan.
Not only that, but the time at the center is different than the tip!
The faster you move through space, the slower you move through time.
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August 09, 2026, 11:04 AM
mttaylor1066quote:
Originally posted by HRK:
Not to be that guy… but this quote is, at best, a mathematically incorrect statement.
Taking the “square roots” of any two side(s) of an isosceles triangle does not automatically equal the “square root” of the remaining side.
What the Scarecrow is trying to quote is the Pythagorean Theorem. To wit: “the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares on the other two sides.”
Famous movie mistake. Now back to our regularly scheduled program featuring fan blades, cornbread, sonic booms and theories of relativity derived from acid flashbacks…
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August 09, 2026, 11:39 AM
V-Tailquote:
Originally posted by mttaylor1066:
What the Scarecrow is trying to quote is the Pythagorean Theorem. To wit: “the area of the square whose side is the hypotenuse
For all intensive porpoises, the correct statement is: "The squaw on the hippopotamus is equal to the sons of the squaws on the other two hides."
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