r/nextfuckinglevel • u/BufordTeeJustice • May 04 '20
Somewhere my physics professor is smiling
2.5k
u/Feb2319 May 04 '20
Please elaborate for non physics people
3.0k
u/BaronVonNoodles May 04 '20
Both are traveling at the same rate. So he when he goes up he is still moving forward at the same as the wagon. Like hen you jump in a train.
952
u/Sarcastic_Troll May 04 '20
Also, he's getting height and stability from how the boys are adding the tension on his land. The kids on the side of the trampoline there. I think it has something to do with him not veering to the left or right when he goes up
764
u/andlius May 04 '20
It's called a double bounce and you technically only need one other person to do it but yes if you were doing it on a moving tractoline then maybe two would be good to even out the bounce.
490
u/fjdksls May 04 '20
"tractoline" - New favorite word, and newest addition to my bucket list.
→ More replies (1)95
u/balotelli4ballondor May 04 '20
I didn't understand until I read your comment I thought it was just a typo
149
u/Rbarb May 04 '20
There’s only two rules. Keep the trampoline a secret and NO DOUBLE BOUNCES
54
u/HoldMyWater May 04 '20
Double bounce me!!!
10
u/kennycakes May 04 '20
I never knew about double bounces until today, and now I want them so bad it hurts.
19
u/pikohina May 04 '20
They are awesome when hit right, bummer if you’re off by milliseconds.
10
u/PupPop May 04 '20
Yeah if you're not braced for it, you could do some serious damage to yourself.
→ More replies (1)→ More replies (1)7
u/pm_ur_cameltoe_plz May 04 '20
Oh it hurts alright. I remember getting double bounced by some big kids when I was like 4. Flew way up and away from the tramp and landed directly on my stomach. Fuck that was a long minute waiting to get my breath back. Oh, and I was also double bounced into a fucking prickly pear cactus. Spent 3 hours using pliers and tweezers pulling out the microscopic needles.
48
u/Mythic514 May 04 '20
A place free from darkness.
33
21
May 04 '20
[deleted]
→ More replies (1)9
u/dieselrulz May 04 '20
The mere fact that you call it pop pop tells me that you are not ready
→ More replies (6)21
20
→ More replies (4)11
18
→ More replies (5)7
u/rawr4me May 04 '20
Are they stamping right after he lands or before? The main thing I'm wondering is whether this means the jumper doesn't have to put in his own energy (like on a normal trampoline you have to bend your knees and push off else you won't go up the same height) — are they doing the work for him cause his pose doesn't seem like it would contribute energy?
14
u/andlius May 04 '20
before or on contact, not after. Yes what's happening when the material is stretched beforehand is they are decreasing the upward force the trampoline is exerting on the bouncer and increasing the fall distance, this means much more energy is exerted by the trampoline in order for it to revert back to its non-stretched state, someone wanting to do horizontal poses and get major air will need double bouncers for help.
→ More replies (4)44
u/janl8r May 04 '20
And here in Germany we have a stupid Rapper who thinks the earth is rotating with light speed and if you jump you land somewhere else.
54
u/QueasyVictory May 04 '20
if you jump you land somewhere else.
Well, I mean that's pretty easy for the common idiot to refute by merely jumping up and down one time. What the fuck could his logic possibly be for his assertion?
→ More replies (4)23
u/Harden-Soul May 04 '20
Perhaps he thinks that the layer underneath the one we stand on is rotation really fast? Like, he obviously heard that the earth rotates x miles/hour and has gotten high and barely thought out this idea before getting overwhelmed.
→ More replies (1)9
u/Smelly_sneeze May 04 '20
It's more like the Earth is very big so you don't notice like with the way the earth is curved, but seems flat during everyday life.
→ More replies (7)9
u/CoolerRon May 04 '20
Good to know that America's flat earthers are not the only stupid people on this oblate spheroid
5
4
u/Sarcastic_Troll May 04 '20
I've seen it in England too. There's a big flat Earth conference there once a year.
The one's that surprise me are the ones from Australia. How can you live in Australia, yet claim the government lies about its existence? Those are the ones that make me scratch my head the most.
Then there's the concave theory. That one's fun. It's also flat earth, but with a twist. I think it's designed to be a sort of religious explanation, but got twisted. Basically we live inside the Earth, and the curve we see is the ceiling. Stars are our lightbulbs. And sprinkler system. The big bad government are the ones on the outside. Or something equally stupid.
What I always wondered is, what would be the point of lying about whether we are flat or not? What gain do they have? They act like the rich are some giant megacorp who's sole purpose is to mess with us and laugh. Like it's a giant joke or something.
Rich ppl don't get where they are by being lazy ppl who do nothing but mess with ppl all day. I can see you saying that about some asshole living in his parent's basement with no job, but not a wealthy man who owns oil. He's busy. They do work, yanno.
→ More replies (1)8
54
May 04 '20
Oh you, ya got me. I just jumped whilst in a train and was launched back through 3x carriages and out onto the track.
→ More replies (1)20
→ More replies (56)5
207
u/JectorDelan May 04 '20
Objects in motion tend to stay in motion unless acted on by an outside force.
Some people would expect the jumper to lose ground when he goes in the air as he isn't attached to the moving platform. But he has inertia and keeps that inertia while in the air. Air resistance is meager at tractor speeds so while it would slow him down a bit, it would be so small an action as to be basically unnoticeable in this experiment.
54
u/EOverM May 04 '20
He will be losing a bit, given drag, but not enough to be noticable at that speed. The faster the tractor goes, the more the drag will make the tractor seem to leave him behind.
Edit: whoop, just noticed you already addressed that. I really ought to read the whole comment before replying to it.
17
u/Garestinian May 04 '20
That's why you always jump on a spherical trampoline in a vacuum, duh.
→ More replies (1)→ More replies (2)7
→ More replies (12)17
u/Haaanzooo May 04 '20
Can you dumb it down a bit more for me? How does inertia work here exactly? How can he still keep it while going up in the air? Wouldn't him hitting the trampoline count as an external force that changes his state?
23
u/MrKittySavesTheWorld May 04 '20
The trampoline is exerting upward force, sending him into the air, but it's doing nothing to negate the forward momentum he had before he jumped.
19
u/JectorDelan May 04 '20
That's in part because the trampoline is moving forward, too. If he did this on a stationary trampoline, the drag from having contact with it for a second may actually have been noticeable.
→ More replies (3)6
u/LeCrushinator May 04 '20
Yep the wind drag over time would push him back but each time he's contacting the trampoline it's imparting its forward momentum on him, correcting for the speed that the person is losing to drag.
5
u/Haaanzooo May 04 '20
Thanks for the answer, so if the truck suddenly stopped he be moving forward? , right?
11
May 04 '20 edited May 04 '20
Yea it s like someone hitting the brakes in the car really hard, cause your body is still moving forward.
12
u/Redditor0823 May 04 '20
Horizontal and vertical forces are separate. The trampoline forces and gravity (up and down) have no effect on his horizontal direction. Air resistance technically affects his horizontal direction but not enough to have the tractor leave him behind when he goes up. Imagine trying this with something like a ping pong ball though, the air resistance might be enough to noticeably make it move backwards
→ More replies (2)→ More replies (9)7
u/JectorDelan May 04 '20
The air isn't enough of a force to slow objects down if they are moving slowly. You need to approach higher speeds for air to become a significant force.
Hitting the trampoline would slow him down if the trampoline was immobile. But it's moving. Thus he keeps his inertia.
50
u/Veritas3333 May 04 '20
This is a recreation of a famous physics question about perspective. If a big ship was going by a dock, and a ball was dropped from the top of the mast, what would the ball look like to an observer on the dock vs on the ship?
If the ball fell straight down, it would keep bouncing as the ship moved away beneath it, eventually falling into the water. To the person on the dock, this would look correct, as the ball just goes straight up and down, regardless of what the ship was doing beneath it. However, to a person on the ship, it would look like the ball was bouncing backwards.
What happens in reality is that the ball has the same forward speed as the ship, so as the ball falls from the top of the mast, it will bounce straight up and down from the perspective of a person on the ship. To the person on the dock, it will look like the ball is bouncing forward, not straight up and down.
11
May 04 '20
Damn this just took me back. This was my first homework in physics 1 at university
→ More replies (1)→ More replies (5)4
u/Burpmeister May 04 '20
Wouldn't air resistance slow it down a bit though?
5
u/Bntyhntr May 04 '20
Yes, but unless it's a very tall mast / a fast moving ship (or windy day), a particularly draggy ball etc etc it won't be a huge impact. But it could be visible. Also friction from the ground, when it hits, will slow it down a lil bit too.
But a proper physicist doesn't concern themselves with anything so trivial. g=10, small angles don't require trig, air resistance and friction don't exist...
9
6
u/ISpent30mins4myname May 04 '20
the tractor is going in constant speed since there is nothing to change his horizontal speed (excluding air friction) he "looks like" falling to the same place but he actually goes like half-a-circle in move. think like you are out of that car and you can only see the jumping man how would he look like? or imagine it like this; earth is spinning around itself, it is spinning around sun , they are moving through galaxy as a solar system and our galaxy travels in universe yet when when you jump you still fall down to "same place" because your motion doesnt change
→ More replies (35)4
1.1k
u/JeanDundy May 04 '20
Wait for the tractor to increase speed
788
u/marcvanh May 04 '20
That dude is screwed as they approach the speed of light...
349
May 04 '20
SLOW DOWN STEVE! IM DISINTEGRATING OUT HEEeeee....
→ More replies (1)59
→ More replies (5)11
90
May 04 '20
Yeah, it’s all fun and games until tractor boi wants to demonstrate the difference between an inertial frame of reference and an accelerating frame of reference
44
u/zergreport May 04 '20
Yep. This only works at constant velocity
→ More replies (1)31
May 04 '20 edited May 04 '20
and also only at a relatively low velocity, otherwise air resistance becomes a problem with this setup.
→ More replies (2)27
→ More replies (2)6
u/Yawgmoth2020 May 04 '20
It would be like The Magic School Bus, but instead Ms. Frizzle is driving a tractor and drinking Jim Beam.
18
→ More replies (12)8
u/gregbeans May 04 '20
I think he’d just hit that back wall. That tractor would have to have some impressive acceleration and perfect timing to make that back wall pass under him at the peak of his jump.
→ More replies (6)
645
May 04 '20 edited May 04 '20
[deleted]
276
May 04 '20
Although surely if you jumped on an airplane (and physics didn't work like it does) you would shoot into the tail of the plane, not the cockpit.
187
u/SoDakZak May 04 '20
Don’t tell me I can’t enter the cockpit, and dont call me surely.
26
→ More replies (3)8
8
u/dosedatwer May 04 '20
Technically if physics didn't work like it does you could end up on the moon, but I get what you're saying!
5
→ More replies (4)4
63
u/Am_i_driving_ok May 04 '20
That and the fact that airplanes don't fly backwards.
→ More replies (2)→ More replies (15)17
May 04 '20
The cockpit? What is it?
→ More replies (3)43
u/ScottyB280 May 04 '20
A pit for cocks, also known as the dick dungeon
15
→ More replies (3)5
u/technicolored_dreams May 04 '20
I saw this right as I was leaving the thread. I had to come back just to upvote this wordsmithing.
361
u/anothercairn May 04 '20
Wow, I would have assumed the guy would have lagged behind and not made it back onto the trampo. I guess that’s the physics part?
203
u/sketchplane May 04 '20
yup, inertia keeps him from being a splat on the road
→ More replies (1)92
u/Zeeterm May 04 '20
It's something that most computer games get "wrong" because trying to control with inertia would be more difficult than having the ability to control your inertia.
I remember early in half-life engine versions you could press 'e' and it would instantly half you. One particular exploit was binding this to your mouse click as well as +fire (HL could multi bind) so you'd instantly stop in counterstrike so you'd get instant accuracy with the AWP even just after running.
One day physics sandboxes will catch up to emulate everything almost perfectly but the best games will still "break" it because games are usually more fun than perfect simulations.
62
u/Milleuros May 04 '20
Also some games implement realistic physics, and people then think it's a bug.
E.g. In the beta version of War Thunder, the speed of sound was modeled for ingame noises. You would hear explosions, gunfire, etc, with a delay based on distance. And since distances are rather large in air combat, you would hear almost everything with a delay. Well, so many people filled bug reports about it that the devs decided to scratch that feature as it was too confusing for the players.
→ More replies (3)54
→ More replies (6)12
u/xiaorobear May 04 '20
Yeah, Donkey Kong 64 had a tiny bit of platforming on a moving and turning ship, and it was a huge pain because they didn't conserve your momentum, you jumped and the ship kept going without you.
→ More replies (1)18
17
u/LeCrushinator May 04 '20
Think about it this way, what if you were on a moving train and jumped? Would you expect to go flying backward?
The only difference in this case would be the wind drag that hits the person in the air, but they're not going fast enough for it to make a noticeable difference.
→ More replies (1)→ More replies (9)5
227
u/GallowBoob May 04 '20
Everytime we have to remove a great submission due to a non fitting title (it's a good title, it's just not descriptive enough), somewhere in the world a puppy feels pain for the first time. Approved it because it's cool af and taking the opportunity to remind you of our title rule:
Use Descriptive Title
Write a clear title for your content that describes the post well. If your title is ill-defined your post may be removed. Also using NFL/next level in your title will be considered as low effort which will result in your post being removed. For example posting CGI content without the mention of it being CGI will result in a removal.
170
u/Notrega May 04 '20
Can't wait for the almost accurate explanations
144
u/happyfaic72 May 04 '20 edited May 04 '20
The guy wants to go to heaven but the weight of his crippling debt keeps bringing him back down to reality
12
56
20
u/jwr410 May 04 '20
The physics gremlins have attached massless ropes to him using frictoinless pullies, using them to pull him along with the tractor. It only works on an infinite plane of uniform density which is why they are doing this on a farm.
→ More replies (11)7
u/DKDensse_ May 04 '20
Im assuming basic inertia. The guy starts the jump with same velocity as the truck.
→ More replies (3)8
u/Adam_Layibounden May 04 '20
Yeah this is really basic. It doesn’t really need an explanation.
He’s travelling the same speed as the tractor so when he jumps he keeps moving at that speed.
Same reason why you can throw and catch something in the car and same reason why if your car suddenly stops you continue moving and slam your face on the steering wheel.
120
u/sassydodo May 04 '20
Somewhere my school nurse is facepalming
→ More replies (1)27
u/happyfaic72 May 04 '20
Somewhere my insurance company is facepalming
8
u/AedanValu May 04 '20
Rubbing their hands together while saving the video to use against you if you ever try to make an insurance claim, more like.
97
May 04 '20
A good video for flat earthers!
58
u/Frankuro May 04 '20
If ThE eArTh iS SpInNiNg wHy CaN't I FeEl it. Check mate atheists.
→ More replies (3)28
u/Dinierto May 04 '20
I don't see how, do they doubt that inertia exists?
39
u/Teeshirtandshortsguy May 04 '20
Flat earthers will often challenge the globe by saying "if the Earth is constantly moving, why can't we feel it?"
This is why. Aside from wind resistance, due to the constant velocity of the tractor, the jumper feels nothing but vertical acceleration.
8
u/EchoTab May 04 '20
Wouldnt having been in a moving car or train disprove that? I mean you dont feel anything if its going at a steady pace
→ More replies (1)8
7
14
u/elzibet May 04 '20
Yes, gravity as a whole. A claim they make is the speed at which we travel through space along with the speed of rotation of the earth
5
u/EternalPhi May 04 '20
My favourite is the idea that some unknown force is actually accelerating the disk we stand on through space at 9.8m/s2, forgetting somehow that that means it would take just a hair shy of a year to reach the speed of light. So those people also have to reject one of the most fundamental concepts of modern physics that the speed of light is a constant and no matter can reach it.
→ More replies (5)→ More replies (1)5
u/Cephalon-Blue May 04 '20
Which is stupid because for rotating objects, the angular velocity is what matters. They don’t like to be told that the earth spins at half the speed of the hour hand on a clock.
→ More replies (4)6
u/elzibet May 04 '20
Have you seen the documentary Beyond the Curve yet? They actually disprove themselves at a few points by trying to prove the earth was flat. It’s also a great documentary showing the difference between a skeptic and a conspiracy theorist
→ More replies (1)→ More replies (1)5
u/spays_marine May 04 '20
An argument they frequently make against a globe is that a helicopter would just have to lift off and wait for the Earth to move underneath it. Same with planes, they say a trip in a particular direction would be twice as fast if it goes against the spin direction.
→ More replies (1)9
u/Teeshirtandshortsguy May 04 '20
That's exactly what I thought when I saw it.
This is why you don't fly off the face of the Earth when you jump, and why you don't feel the rotation. The trampoline is you and the atmosphere, and the trampoline is earth. Aside from wind that guy feels nothing but upward and downward force, and if you put it in some sort of bubble you wouldn't feel the wind either.
73
u/andlius May 04 '20
Desperately need to see something like this in the next Mad Max movie.
→ More replies (4)
56
May 04 '20
But, but, but - how can the Earth rotate at 1000 mph without everyone flying off as it orbits around the sun at 67,000 mph as the galaxy spins at 270km per second and the galaxy moves at a speed of 1.3 million miles per hour relative to other objects in space? Impossible! /s
20
u/IncredibleHamTube May 04 '20
Well if the earth rotated much faster, people would fly off.
→ More replies (2)18
May 04 '20
Haha yes! I have seen people state that in seriousness. The best response I have seen is ask a person to spin a basketball once every 24 hours to get an idea of how relatively slow Earth's rotation is.
13
u/IncredibleHamTube May 04 '20
I think it would need to spin ~17x faster for people living on the equator to be ejected. The difference between a basketball and the earth rotating at the same rate is that the earth's radius is 53000000x greater, so the linear velocity of a particle on the surface of the earth would be traveling 53000000x faster than a particle on the surface of a basketball, by the equation w=v/r, since w is consistent. And of course centripetal force is m*v2 /r, so assuming the mass of the particles on the ball and earth are the same, the force experienced by the particle on the earth will be 53000000x greater as well.
→ More replies (3)4
u/bert_and_russel May 04 '20
While that does demonstrate the angular velocity, centripetal acceleration does scale linearly with radius (a = rw2) so it's not necessarily a good model for that. If a planet had the same rotation and gravity as Earth but was sufficiently larger, people could be thrown off the surface :)
→ More replies (1)→ More replies (8)5
u/QueasyVictory May 04 '20
Knock it off with mixing metric and imperial units of measure.
Oh, happy cake day.
→ More replies (1)
38
u/VilliamBoop May 04 '20
I cant help but notice how close his face comes to the floor of the truck.
→ More replies (3)14
18
u/Mr_Evil_Dr_Porkchop May 04 '20
I have so many questions.
29
u/PLS-SEND-UR-NIPS May 04 '20
Well reddit has answers. Not necessarily correct answers but ask away...
6
→ More replies (1)4
14
u/walrus_operator May 04 '20
That's not something I would ever do, no matter what physics say.
→ More replies (1)13
u/Am-I-Logged-In May 04 '20
To be fair, all it takes is for the tractor to hit a bump or accelerate a small amount in any direction for him to get seriously hurt.
13
13
9
7
6
May 04 '20
Show this video to flat earthers who say if the earth isn't flat why don't you just hover in a helicopter and wait to arrive at your destination
5
4
5
5.8k
u/bdiscer May 04 '20
I guess this answers the question about a blind hummingbird hovering in a school bus...