What happens when a chain ladder lands on a table? Great video and concept by Andy Ruina. Let me know if you want me to post a follow up explaining the answer.
Because the bars are tilted which means the edge of the bar will hit first then the rest of it, and when the edge hits first, that edge acts like a pin where momentum of falling rotating the pin and pulling the other edge with the short rope faster than the falling speed, and with multiple bars, this phenomenon can be observed and proven
@GoldDominik893 Says:
Less air resistance
@BentleyTranPhucnam0631 Says:
the other one got pulled down
@AbsuEngur-g3h Says:
Drag force: the falling ladder hitting the table has an air-drag area that keeps shrinking, while the other ladder, falling freely, has its full drag area slowing it down. You can test if that is correct by doing the same experiment in a vacuum. My hypothesis is that they will fall in the same time in a vacuum.
@gijsrozestraten4954 Says:
Why did Building 7 fall at freefall speed?
@markoasdadriver6285 Says:
Didn’t expect that. The one on the left having hit the table has less weight pulling it down so should be last to finish, or so I thought 😮
@SantanuProductions Says:
Humans proudly debate the universe with a brain that evolution designed mainly to stop us from becoming lunch on the African savanna.
Newton looked at gravity and said, "That works."
Einstein looked at the same gravity and said, "Only if you don't look too closely."
Our brains were never meant to understand black holes, quantum mechanics, or spacetime. They were meant to spot lions in tall grass and remember where the berries were.
Science is what happens when a Stone Age brain refuses to accept its job description.
@АнжеликаКискова-я9ж Says:
It's the shock of impact on the lower end pulling the higher end down thus speeding decent.
@dond668 Says:
They will fall at the same rate in a vacuum
@Ad0rak Says:
my guess is that the flexible rope is a column in free fall - so acceleration is limited, whereas it bending due to hitting something allows for faster acceleration
@thesearchforterrestrialint7795 Says:
its the links in the latter pulling downward as the links seek resting state in between the steps they push outward when they push outword they also pull downward
@donheady3851 Says:
The initial bounce from the rungs sends backforce up and then pulls it back down again giving it an extra pull. Well. The same extra pull, but quicker because it's gotta travel a smaller distance. Like waves compiling on eachother then speeding up cuz their resonances match.
@PrathviiXD Says:
tension force
@Battlebee07 Says:
A chain ladder hits a table faster than in free fall because collision forces from the table create torque, which pivots the rungs and exerts a downward yank on the remaining chain, accelerating it. This phenomenon, created by Cornell Professor Andy Ruina, occurs because the impact converts potential and kinetic energy into a rapid, cumulative downward force on each link as it strikes the surface.
@dkazmer2 Says:
Why don't you just tell me
@defenderoftheadverb Says:
My guess - air turbulence slows down the long one more than the short one. Test it in a vacuum.
@jonnygudman1815 Says:
because, upon impact, the steps are briefly pulled down via the connections, thereby momentarily increasing the acceleration.
@PaPooKr Says:
Tiny tugs on the ropes above by the bouncing of the sticks below
@tomlinton9959 Says:
As each of those angled sticks hits it give the upper end a slight jerk speeding up the ladders fall
@daltonbeltran Says:
Both ladders are under the same gravitational acceleration, so their centers of mass must accelerate downward at the same rate. However, when one ladder lands on the table, part of it is already supported and stops moving. As more of the ladder piles up on the table, the center of mass of the remaining moving part shifts upward relative to the ladder falling all the way to the floor. To keep the overall center of mass accelerating downward at G, the free end of the ladder must move downward faster. That is why the ladder falling onto the table appears to fall more quickly.
@Badhabit4590 Says:
The bottom is closer to the left ladder people
@FewNuttyNeurons Says:
Shorter length of travel = less friction = quicker
@suniltshegaonkar7809 Says:
free fall is faster, because velocity of free fall keeps increasing due to gravity, F = ma. Other ladder fallen on table has stopped moving already.
@davidcopola3783 Says:
The impact and the angled step bars of the chain ladders are the reasons. It creates additional accumulative tension on the connecting ropes as each dtrpping bar hits the table top.
@springsexterior Says:
The answer. Think of a wave hitting a sea wall and vibrations back and forth causing almost a pulling effect against the rest of the water behind it, making the waves bigger as the splash behind it and bouncing forth again.... Spectra. It's pretty simple actually! Just like you described in your wave video! The same thing happens here. Waves start happening and they start being circular. But unlike water! Where a wave effect is balanced out by a buoyant almost equivalent solid below it. Both sides have free air and only the tension of the ladder above it! So it pulls down on it self. And no it just took me a second to think about it not an engineer not a mathematician!
@Gary-V715 Says:
Its not falling faster. As the rungs stack up at the bottom, the distance to fall becomes less making it appear to fall faster.
@MAYCO0516 Says:
Both ladder are initially falling at the same speed generating the same amount of energy. The ladder that hits the table, end up being a smaller system for that energy to be distributed through, therefore it is able to fall faster
@jeremivits9520 Says:
easy i found it in 30 sec, the chain on B ladder is speeding up the fall ont each step hit, you welcome!
@jaetran1695 Says:
i can't stop watching that...
@sgransar Says:
The one that was hit with an airplane.
@gsh64 Says:
Easy!
The left ladder sticks went sideways a little when they reached the table, so they gave a pull to the rope as much as the vertical vector of that pull was.
@non-binaryjesus Says:
Velocity and gravity. Rebounding forces pulling on the ladder
@AM93D Says:
the distance of ladder B gets shorter with time
@samishiekh Says:
The strings experienced a whip on contact with the table which sent them is different directions. That movement pulled on the next step of the ladder and these micro-pulls contributed to move the ladder faster
@nickclarkuk Says:
Reduced system wind resistance of the total ladder ?
@RawwDogg Says:
i suppose less friction but surprised the less friction of the air would have been enough for such a dramatic difference in such a short distance.
@OnurKula Says:
Aerodynamic difference
@meyoxes Says:
the left side has less air resistance?
@Hammeredprawn Says:
The first ladder hits the ground and because of this the ladders tension changes and causes a slight increase in downward force, the ladder in free fall does not change because it has not yet come into contact with the ground causing this change in tension ? I dunno.
@ageisfang8566 Says:
my guess is the bouncing/rolling ladder segments pull at the rope making the ladder get pulled faster.
@freecalradia Says:
Wenn ich raten müsste und mehr tue ich hier nicht: Die Teile der Tisch-Leiter bleiben nicht still liegen sondern prallen nach ihrem initalen Aufprall nochmal ab. Bei der darauffolgenden Abwärtsbewegung dürfte ein zusätzlicher Zug auf dem Seil der Leiter liegen, welcher die Abwärtsbewegung beschleunigt.
@stelmobd Says:
Air resistance is greater for the free falling
@FreshMeatballs Says:
Because of the angled rungs when each lands it pulls down on the shorter rope
@SaulGoodman-hx3sv Says:
Torque generated due to gravitational pull which again pulled the above attached steps connected through the strings. This is my assumption.
@ilmrahil Says:
The rods are not parallel to the ground; consequently, they strike the table at only one end. This initial contact generates a small downward force—however slight—at the opposite end of the rod. Each falling rod creates a minor shock wave and a tiny downward-directed force at that other end. Once a certain number of rods have struck the table, the cumulative effect of these forces creates a significant difference.
@dawoodbanday6267 Says:
Tension through the thread passes at the speed of sound, and pulls it faster.
@OphielPan Says:
Ok now i wanna now how
@sp1cule Says:
of course theres pulling force
from the other threeads on B
@TrueTexan87 Says:
Lateral acceleration from deflection of the rungs pull taught line down faster.
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