Spyke
sh.itjust.works

What cracks me up is the piece of metal, labeled metal, attached to the one metric ton of... Metal

127

Well, the metal sees the magnet and wants to eat it so it move toward it. It's the ol' Magnet on a Stick trick and metal is easily fooled.

5
lemmy.world

Fun at partys guy: While the car will actually experience a force torwards the magnet, so will the magnet experience an equal amount of force torwards tha car. Given the connection between the car and the magnet is stiff, these opposing forces will stress the connection and create a reactive force in there according to Newtens 3rd law, ultimatly canseling the forces out and neither the car nor the magnet will move.

If you however remove the stiff connection, the car and the magnet will move torwards each other untill they meet.

84
affiliatereply
lemmy.world

what if you just attach a second magnet to the car so that it pulls the first magnet forwards?

10

Then you have the same mechanism used in toy wood trains.

23
lemmy.world

How about if you launch a huge magnet well above escape velocity and remotely anchor a space elevator made from a ferromagnetic material to it but the space elevator’s weight counteracts its inertia exactly and holds it in place perpetually. Would that work?

Edit: I swear I’m not dumb, I just didn’t think this one through.

5
Natanaelreply
slrpnk.net

It needs to rotate unless it's a superconductor.

Also a magnet that size would mess up navigation equipment for miles

4
lemmy.world

It will, but why do you want the truck to attract the magnet? Are you going to drive backwards everywhere?

80

This illustration does not imply that the car is moving. There are no "speed lines" or arrows that would indicate that.

So the illustrated setup would 100% work.

58
5in1kreply
lemm.ee

I hit 60mph and am like 20 miles from my house. Why would you tell me to do that?

55

At least you didn't pull upwards like I did. Glad the ceiling was there or it could've been much worse.

11
feddit.de

Good old troll physics.

W...wait, why is the troll head missing?!?

49

I built a scale model to prove the haters wrong. I had to tilt the platform a little for it to overcome friction, but once I did, the car rolled forward until it hit a wall.

34
sh.itjust.works

So this would work actually but only for a brief second as the electrical current generated by the frame of the vehicle passing through the magnetic field would disrupt the flux conduction in the magnet. This is mostly due to being the way that it is.

32

Could we fix it by constantly increasing the (electro)magnets strength?

0

Less fun at parties guy: While the diagram leaves it somewhat unclear as to what precise effect that mechanism is intended to achieve, clearly it involves electromagnetism and thus any proper explanation must begin with a full description of quantum field theory...

29
lemmy.world

What's funny is this would actually work if you just pointed the magnet at other people's cars.

27
drislandsreply
lemmy.world

"this would work if you did something completely different" lmao

9
GoodEye8reply
lemm.ee

Depends on what we consider wrong. Could you pull a car that way? Theoretically, yes. Could you save energy that way? No, because the car driving in front would have to do extra work to overcome the magnet pulling it towards the car behind. You can't cheat the first law of thermodynamics.

2

But that's not my energy, the guy in front now has to pay for me to be his trailer.

Also unmeme for a second, wasn't there news that we were able to harvest energy from brownian motion about a year ago? What happened with that?

1
Phoenixzreply
lemmy.ca

It would only work if you manage to keep the car at an extremely precise distance from the car in front. If you're off by tiny tiny amounts, you'll either lose the magnetic attraction, and stop, or you'd started getting closer fast until you'd be stuck to the car in front of you

3
lemmy.world

Being stuck to the car in front of you is more efficient for traffic anyways

4
lemmy.world

We could chain them together and make the front car really powerful. The other cars wouldn't even need engines!

It would get kinda hard to control though. Maybe some sort of track system could keep it steady?

4

That's some crazy Elon musk idea, making a brand new mode of transport

1
Rakonatreply
lemmy.world

Use two magnets of opposing polarity, the stronger magnet should be on the bumper to push the boom forward, and drag the truck with it. /s

2

Because both of the magnet's poles are pointed at the car and the attraction and repulsion are canceling each other out.

24

The mount is holding the truck back. You need a wireless magnet.

21
sopuli.xyz

This is actually kind of how electric motors work as the rotor chases a magnetic field forever kept out of reach by the stator, and you can't tell me otherwise.

21
FuglyDuckreply
lemmy.world

The difference is, that the rotor is allowed to move, and they’re switching coils in the stator to keep it going.

In this system, the force pulling the magnet towards the truck is being negated by the arm fixed to the truck.

If you placed a bunch of electromagnets on the guard rail, that would be more like a motor (technically, a linear motor,)

16

It's because the magnet is in the vertical position, it needs to be in the horizontal position to properly complete the circuit

19
lemmy.world

It's actually a common misconception that magnets always attract metal. This misconception was popularized by people joking that magnets are magic. In reality, magnets attract because they have magnetions in them. These magnetions allow them to attract things like metal but a little bit is used up each time. Eventually once the magnet's magnetions have been depleted, the magnet turns back into a newt and goes home to recharge.

17

Science is trying to find a way, but for now you need a witch/wizard to recharge it.

6

because the truck is self-propelled, and it can only go as fast as it takes itself. Therefore the magnet, which is attached to the truck, can only go as fast as the truck takes itself.

16

easy: the metal is pulling the magnet backwards and the magnet moving backwards is pushing the whole truck backwards through the arm.

(explaining things wrong is a fun hobby)

14

Why not just use rope instead of a magnet? You wouldn't need the extra metal on the front if you did that and would save weight.

9
lemmy.world

Mythbusters did a similar one using a fan and a sailboat. The boat moved. Backwards.

9

That one worked because it was just an inneficient way of pointing the fan backwards, the center of mass, as the average of the position of all the mass doesn't move from inside forces, just outside ones, so for the car to move the mass of the magnet and arm would meet to move in relation to the car, because they can't, the car doesn't move too.

Wich is basically just a long way of saying "Newton laws".

1

The large array of third party lighting fixtures exert photon pressure enough to cancel out the magnetic pull

9

It will work fine of your intention is to secure the arm so that it won't dangle when you drive

6

For the same reason why this device does not go left by the metal slab pulling the magnet to the left

6
lemmy.world

Jim Knopf und Lukas der Lokomotivführer (Jim Button and Lukas the Engine Driver) dit it first:

5
Matomboreply
lemmy.world

They even got one step behound: The two rocks you see in the drawing are actually a broken up magnet into it's north pole and south pole, so it's only magnetic when they connect the both with a metal rod. Genius. (ofc that's EXACTLY how magnets work)

3

I also find it funny how i got introduced to the troll physics meme 20 years before it was called that, as a small child back in the 90s

2

You moron, that would make the car flip, you need to attach it to the back of your car horizontally

2
lemmy.world

Me sighing as people akshually comment explaining the obvious in a meme sub. 😅

2
lemmy.world

Hey now, I'm not an engineer So the first time I saw this a few weeks ago it kinda blew my mind and I really had to think it through. Please don't shame people when they need to take a moment to think things through.

22

Hold up, I'm not shaming anybody who wants to think things through. You're more than welcome to, as you do in your regular day to day. I just think it's funny that people feel the need to over explain anything and everything on Lemmy even the troll stuff they see in a shitpost, which is very different. Don't overload my comment with a take, please, that's not what I'm doing.

0

Sure, but only because you asked. The magnet applies a force on the metal block, and the metal block an equal and opposite force on the magnet. The force is dissipated as a compressive force along the arm. All forces cancel out, so no net force is applied on the body.

Source: statics & dynamics 1

7

They are connected in the same system. What the truck is doing is the same thing as you holding two magnets together, you won't go anywhere because everything is self contained.

Edit: this is probably not a very accurate explanation but it's the way I understand it.

3

If the arm can bend, the car and the magnet could move towards each other until they come together, moving the car at max a few centimeters. If the arm doesn't bend, the car is pulled as much forward as the magnet, and therefore the arm and in turn the car itself, is pulled forward, leaving the whole system stationary.

2
Lemminaryreply
lemmy.world

You realize I responded when there was only one comment, right? Please look at the timestamps if you're gonna accuse anybody like that.

-1
Krauerkingreply
lemy.lol

Then why use plural people? You pre-emptively complained about something that wasnt much of an issue and then got upset when people got excited about a silly physics puzzle/riddle?

1

Then why use plural people?

Because it happened in another thread I was reading. It's a common pattern on Lemmy. Simple as.

You pre-emptively complained... then got upset

I did not pre-empt and I did not "complain", and I certainly did not get upset 😂🤣 What is this. If anything, I'm more surprised I'm getting this type of flack over an innocuous comment.

You're just willingly misinterpreting everything I did to paint a warped picture of me. Restrain yourself, please.

Realize that the sigh is not from exasperation but of "these silly folks" as indicated by the emoji. Jesus Christ, not only do people love over-explaining, but y'all will impulsively look for any reason for a witch hunt.

1
Lemminaryreply
lemmy.world

It's a troll post in a meme sub. Idk what to tell you... Sure, I guess?

0

You need a magnetic personality to make this work. No personality, no movement. And if you have a personality that pushes things away, the car might explode.

1