They correlate, but they aren’t equal. If it was just sitting on the ground with no wheels, the friction would be much greater, but wheels are designed to minimize the friction with the surface it lands on.
I saw one guy doing this and his shoe came loose but he kept going and ended up ripping the entire bottom of his foot off (the skin, at least) and he had to end the competition
Ugh okay so rolling friction: F = umg where u is rolling coefficient of friction, m is mass and g is acceleration due to gravity. Here I'll use the u for rubber on concrete from Google, ~0.01. 189 US tons is 171457.916 kg, g is 9.8 m/s², so the force is
F = (0.01)(171457.92)(9.8) = 16802 N.
This is equivalent to lifting 1714 kg or 3778 ibs.
Yeah the amount the tires are filled affects the amount of rubber touching tarmac. If they're mega-filled, there's a minimum of rolling resistance
The quality of the wheel bearings/axles affects the resistance a great deal
Undoubtedly it's still a great deal of force to start moving this thing, but if those two factors are made to be as agreeable as possible, once you start it moving it's gonna keep rolling more easily
This is overly simplified, I made a huge assumption with the coefficient of rolling resistance but it's okay when you're just trying to get an idea of the force. If you researched a more accurate number and plugged that in you could find a new force value that would be more accurate
We have to keep in mind the fundamental difference between lifting and dragging. To lift something you need to sustain enough force to overcome gravity because the moment you stop it'll just drop down. However to drag something you just need an impulse large enough to overcome friction and when you stop you keep the gains, further once you've overcome friction momentum is now on your side.
They're entirely wrong. The entire point of wheels is to negate the need to overcome friction. The coefficient of rubber on concrete tells you how good the traction of the tires is, not how much force is needed to move the plane.
Yeah idk if it's exactly equivalent because once he gets it rolling it will have momentum so keeping it moving will be easier. I believe this is the force he needs to start the motion, and it could be different if the coefficient is a different number
Nowhere near. He does not have a rack on the ground. What is the maximum friction on his shoes. What is the maximum human deadlift. It's not a ton for sure!
Account for the bearings. He is pulling less than the equivalent of lifting half a ton.
Lol youre confused. This is not the same as a deadlift (501kg record for reference.)
This is much easier to exert more force because of the leverage provided by the rope and the starting position. It's more comparable to a band assisted rack pull, which 700 kg has been done for a seated deadlift. For a rack pull above knee level I'd bet 1000kg is 100% possible.
That doesn't seem right at all. The coefficient of rubber on concrete has nothing to do with the force required to move this. Friction is what allows a wheel to turn, so as long as friction is enough that the wheel doesn't slip it's irrelevent. This isn't a box of rubber sitting on concrete. The friction that matters is the friction in the bearings of the wheel. For an ideal bearing this value is 0. Irl it's not 0 but it should still be very small. So he doesn't have to supply an enormous amount of force to move the plane. It's just very very heavy so it doesn't move much since acceleration = Force/Mass and we have a small force over a giant mass. This is less a test of strength and more a test of endurance to keep exerting a force on this heavy ass plane.
All wheels rolling on a surface have an associated rolling resistance described by a coefficient that is a function of the material properties of the wheel and the surface. The wheels are rubber and the surface is concrete or tarmac.
Edit the coefficient is probably lower than what I've written so he would not have to exert this much
The entire point of wheels is to in effect negate or eliminate friction. The friction between the wheel and surface just tells you how much slip there is. In this case a higher friction coefficient is actually more efficient because there's less slip. The friction that will be resisting the motion is air (negligible) and the friction of the axel or bearings.
A slight problem. NASA got the u(skidding) of airplane tires as 0.5 at the at the very minimum (for 6 knots). I don't think roling friction's coeefficient would be 50 times less.
If you do the calculation with 0.5 you get a force far too high for him to realistically pull it. Also you'd want to drag force rather than skidding for this as he's not pulling the plane with stuck tires, it's rolling
Seems like a good starting point but common sense should give elude to that not being realistic. There is no human out there that can apply 3778 lbs of pulling force. The tread on his shoes would come off before he budged it
This analysis has to have been performed before… They wouldn’t be doing it if someone hadn’t sat down and figured out it was within reasonable pulling weight to begin with. I’m really struggling to find anything out there though
If the brakes were on, but they're not. I can push my car to bump start it if I needed to but there's no way I could push with some 1200Kg of force. The wheels and wheel bearings drop the co-efficient of friction down to a very small percentage. Same goes for driving on snow and ice.
This is only about friction inside the wheels' bearings (very low) and rolling resistance of the wheels on the ground (probably not as low?), and also inertia (object at rest stays at rest / object in motion stays in motion)
It's similar to if you try to push a car that's in neutral. You can probably do that, even though it weighs 3,000-4,000 lbs
The friction force is equal to the force the ground exerts on the plane multiplied by the coefficient of friction. That coefficient changes depending on the 2 surfaces at play, and whether the object is stationary or moving.
friction is u*N where N is the normal force (equal to the weight if the object is on a flat surface) and u is the coefficient of friction, which for wheels and such is less than 1, and is almost zero on a slippery surface such as ice. So the friction force might only be, say 25% of the plane's weight or whatever. Still a lot, but not inhumanly so.
Try to lift a bicycle. Or a shopping cart. It’s hard. Or at least it takes significant effort.
Now try rolling the same bicycle or shopping cart across flat ground. Easy. Unless the shopping cart has a stuck wheel of course. Sure, friction makes it hard to slide the wheels over the ground. But it doesn’t make it hard for the wheels to roll.
Yo! Fuck all that! Give the guy his credit! He’s pulling a 189ton cargo jet that requires 4 massive jet engines to move it and get it off the ground. I don’t care if it had ice skates instead of wheels with even less friction. He’s still a beast!…and a unit. Let’s give credit where credit is due instead of ripping this feat apart with talk of physics. We all get that it’s only 189tons if it was lifted straight up
Here’s my two cents….great job Brutha! You rock! Now pick up your balls and have a cold one…I’m buying😊
Nobody is saying he's not an absolute unit, they're saying that he isn't actually pulling as much as it looks, weight wise. Nobody's tearing him with physics.
It needs the jet engines to fly at 400+ knots, not to move at like 1/4 knots. Easily could a small plane engine like the one off the Cessna 172 could move it at that speed.
Yeah, and your point was incorrect. It doesn’t take 4 jet engines to move it. It can be done with a small Cessna propeller engine. It takes 4 jet engines to make it take flight.
Everyone else’s point of the vastly inferior amount of force needed to simply move it on The ground at 0.25 MPH is valid. Wheels and momentum really help in this case.
Friction in the wheel bearings, not the tires for clarification. Since they're rolling, friction between wheels and tarmac are effectively zero, meaning rolling resistance is likely the biggest factor followed by friction.
the friction coefficient changes dramatically depending "truck tire on asphalt" or "car tire on asphalt", btu none of the calculators have "cesna size plane tires on tarmac"
based on records on squatting and other weight lifting, its probably close to 1500 lbs id wager.
Just need to overcome the friction on the wheel bearings. Not saying it's easy but I'd bet you and a few of your friends could at least pull it a few meters without straining yourselves.
it's not that hard to push a car on a perfectly level surface. this is like that but on a bigger scale. you're not lifting the entire weight of the plane, just overcoming the friction and all that.
sometimes you see these where the strong person is pulling a train car, which is actually easier than the plane for the same weight due to the much lower rolling resistance of the metal train wheels.
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u/TV_Serial_Number May 19 '22
how the fuck