I know how much you like posting definitions, humber. Would you be interested in letting the rest of us in on your strange definition of "behind"?
Split Thread The validity of classical physics (split from: DWFTTW)
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Very simple. When on level ground, the patch is directly underneaths the axle.
When driven, the contact patch will be clockwise of that, so trailing the axle.
Unless you think a steel train wheel can claw itself forward, I think that you must accept that the force trails the axle.
I'm referring to "behind" as you seem to have used it referring to the contact patch on the jeep parked on a hill. I see the axle (or the center of the wheel, at least). I can draw a line straight down from there, toward the cnter of the earth. Seem to me that the contact patch is entirely in front of (and counterclockwise from) where that line intersects the surface. What about this picture causes you to use the word "behind?
Then you should put chocks on the uphill side, to prevent your car from rolling down hill.
I am not going to accept remarks based upon figurative ideas and images.
The former description is clear. If you cannot understand that, then I question your ability to further comment upon the matter.
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Tyres are complex, jjcote. they deform ahead of the load because they are flexible.This is retarding drag, some times referred to as 'plough' .The driving patch is to the rear of the axle, as it must be to drive the car forward. Being braked from rolling down hill produces a reaction like that of driving the car forward. It cannot generate grip ahead of itself.
The cart wheels are rigid enough to be though of as disks.
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That's your best contribution?
Why would you call your remarks 'trivial' ?
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Well done, Captain. Go stand in the corner.
I replied to your PM.
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A wheel with a contact point directly below the axle will spin, but not move. To do that, requires that contact point to move to the rear, but for that to happen yet remain in contact with the ground, there must be a small decrease in the radius of the wheel at that point. The wheel is locally deformed by the force from the axle. That is how driven wheels develop thrust. It is not possible for the belt to force the wheel into that state, so it cannot drive the cart forward, but it can spin the wheel..
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First, still wrong about contact patches.
Second, been told to you numerous times that it ISN'T the belt that drives the cart forward. The belt spins the wheels, the wheels spin the propellor, and the PROPPELOR drives the cart forward. Possible because of the differential in velocity between the air (still) and the surface of the belt (moving), which is the same differential that exists between a road (still) and a wind (moving).
Third, your IT skills seem to be up there with your Physics as, If you've replied to my PM, I've recieved nothing.
Now about Cart videos, Negative Drag and Gas Cavitation.....
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"'When I use a word,' Humpty Dumpty said in rather a scornful tone, 'it means just what I choose it to mean — neither more nor less.' 'The question is,' said Alice, 'whether you CAN make words mean so many different things'".
Simple flat denial. Impressive.
The power of the propeller can not exceed that from the wheels, so it cannot increase the angular velocity of the wheel, therefore no progress can be made to the belt The belt, propeller and wheels are synchronized, so no motion is possible.
Nasty mechanics, lets get back to the safety of equivlance
There is no differential velocity between the cart and the air at "windspeed"
If the wheels of the cart are in good frictional contact with the belt, that is, 'fully geared', then they can never run at any other speed than the belt. That makes it impossible for it to climb the belt, even from going back with it.
Only by being placed by hand, can it achieve "windspeed".
I see that you had a hot mail address, but I responded to the email directly so it was a JREF PM.
I think they call that myopic. Anyway, you need some buttons to play with. Look it up. Drag generates heat, so some of the energy can be used to power regions of negative drag should circumstances allow.
"...but you can make the wind of still air". "Nonsense", said the Queen.
To the rear of, behind, trailing. What can it mean? So many options!
Well of course it's the one direction that gives you problems, that you don't understand.
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Hey, that's Humber Plan D! No fair cutting in like that!
Actually, since I deal with tires and suspension and all that complex stuff for a living, I don't have any problems understanding it. I also have a cart that I can place on a treadmill, start the treadmill and run it up to break even speed, measuring how much drag the cart presents during that time. It's really quite informative; you should try it some time. You might also realize how hard it is to get a steady state condition.
"The belt, propeller and wheels are synchronized, so no motion is possible." Another very false statement by humber.
In fact, the hard part is getting the cart to stay in one place (fore and aft that is). It's either moving forward or backward unless you get the incline of the treadmill just right, the speed setting just right (which is hard because the controls aren't very consistent) and the rear wheel (front wheel in mine, I run the prop at the front) from shimmying a little. I've had to repair the driveshaft several times now because of the cart doing the "impossible" and moving up the ramp and striking the prop against the treadmill.
That's the difference; I can test real things. You can't. You really need to. But you're right, I don't understand why you are always so far behind on these things when all you have to do is listen to those who have done the testing for a change.
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As opposed to JJ showing you a picture of a Jeep with the wheels in contact clearly ahead of the axel. Response- Well I can't talk about abstrastraction (an abstraction being proof you're wrong!)
All the rest covered, proven and ignored by you ad nauseum.
No PM recieved, try again.
Yes, drag can be redirected in several ways. Winglets, for instance, use the wing-tip vortex to regain some of the energy used by the span-wise flow to create them. This is termed a reduction in total drag, not negative drag. You still can't supply one example of that term being used in aerodynamics. I guess "Stop bothering me" is as near to admitting error as you get.
Being the weekend, I assume production of the "magic cart" video is under way? Only a month late, do dead-lines exist in Humbertown?
Now, as to Cavitation is gas......
recursive prophet
Graduate Poster
You guys are a hoot! Good show for a Friday night. I couldn't find the meter either, Ross. But if you just type id between 2 colons, voila!
= Fe+y.
BRILLIANT quote! One of my favorite movies. Much needed diversion from the headache of humberitude.
Oh really!? You know what they race in the humberverse?
This is one of my favorite humber techniques. Falsify the real world data (i.e. "it hovers", "it is simply doing nothing", "the cart does not move"), and then offer a completely bizarre conclusion devined from your fabricated data (i.e. "there is no load").
I'm sure that for you popcorn is complicated.
This is like some sort of avante garde performance art. He even gets wrong wrong.
And now for a selection of quotes that are just too far out there to even comment on...
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"I caught an updraft!" "I'm okay, the ground broke my fall!"
Michael Keaton establishes himself as a farce to be reckoned with. Somehow humber reminded me of that movie:
"I got ideas coming at me all day... I couldn't even fight 'em off if I wanted."
Maybe it's just me.
Love it!
Michael Keaton establishes himself as a farce to be reckoned with. Somehow humber reminded me of that movie:
"I got ideas coming at me all day... I couldn't even fight 'em off if I wanted."
Maybe it's just me.
Love it!
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John Freestone
Graduate Poster
LOL. Logic. Humber, you've said (paraphrasing, I'm not going to waste more of my life finding the exact wording):
It's a circle! (presumably, a wheel)
If a wheel was circular, it would just spin. There has to be some distortion. (following my detailed mathematical description of why)
A wheel must have its contact area behind and bounded by the axle position.
If a tyre is flat, the contact area will include the axle.
An ellipical wheel doesn't count because a wheel is "round". (although an elipse is round, too, and if you mean "circular", then it will just spin according to an earlier statement).
You have no idea about how to make any logical argument. Your views are expressed through the whole of these discussions as isolated statements, most of which contradict others, as the above example would demonstrate, except you probably can't see anything wrong with them because you can't do logic!
"The cart's wheels are rigid enough to be thought of as discs."... (discs are circles. you can't really be saying that except to say that they do not distort at all, so presumably that's why they don't even turn, eh?, but just sit there motionless while the belt moves under them: they have no friction at all, zero. Why the prop, geared to them, keeps turning....?....or is it geared to it?...does spork just make it look like there's a bevel gear in there, and really the prop is just spinning in the still air of the room...?...but not going anywhere...maybe that's because it's not real air?...while the cart is NOT DOING ANYTHING AT ALL with a rubber belt moving under its tyres?....yeah that'll be it.)
Logic? You've said that wheels act like levers, which is not a bad point, but then that they can't cling to a slope by an area upwards of the axle. Why? If I just took all the wheels off and propped the car up on levers attached to the axle, at 45 degrees, little rubber feet on if you like, these pointing down and forward, i.e. up the slope (not a ridiculous cliff-face), with the brake on, would it go anywhere?
No. It wouldn't move, except for bending the levers, etc. The whole thing is trying to fall, which means forcing the axle down w.r.t. the feet, but the brake won't let the axle turn. Replace the brake with a balanced clutch and gas, you've got the same resistance. A bit more gas and it will lift itself, just like jjcote's example (it was jj, wasn't it?) of an ellipse. So it would be perfectly possible to use your own description of how a wheel acts like a lever to work out that it can indeed claw its way forward on the level, up a hill, by putting pressure down a little way forward of the axle. Your problem is just, as we observed and agreed earlier, that you refuse to change your mind once you've plumped for your best guess, because considering humility a virtue would be conceited.
And even that is illogical! You are just conceited, and your ideas are also the other common meaning of "conceits". They're mere flights of fancy, dreams, or, as one dictionary says, "an elaborate poetic image or a far-fetched comparison of very dissimilar things".
It's in the drop-down list under "Specials" when you click [More] on the edit page, or you can just type colon id colon. Maybe that was a rhetorical question, but anyway, that's the answer.
CORed
Penultimate Amazing
I think the schizophrenic Indian from "One Flew Over the Cuckoo's Nest" (the book, not the movie) writhes Humber's material.
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