/sci/ - Science & Math

[Anonymous No.8044566]

The ball gains speed with each magnet. He is getting more energy out than he put in. How is this not perpetual motion?

[Anonymous No.8044569]

>>8044566
He is taking energy out of the magnets

[Anonymous No.8044570]

>>8044569
How much energy does the magnet contain and how did it get in there?

[Anonymous No.8044572]

>>8044570
Im not a physicist I dont know. Fuckin magnets man

[Anonymous No.8044573]

For starters, it's not perpetual. It's a straight line.

[Anonymous No.8044575]

>>8044573
Those are not conflicting conflicts shitlord.
An object can move perpetually in a straight line.

[Anonymous No.8044582]

>>8044575
That particular example is not perpetual, nor could it be.

[Anonymous No.8044584]

>>8044566
The potential energy was already there from the distance between the balls and the magnets.

It's like throwing a ball towards the ground, realizing that it hits the ground faster than you threw it, and wondering where the extra energy came from.

[Anonymous No.8044585]

>>8044582
To elaborate, it would eventually find itself in a rested state, to reset it to the potential state would require the at least the same or more energy.

[Anonymous No.8044592]

>>8044566
What if I put this shit in a circle, senpai?

[Anonymous No.8044593]

>>8044592
It would stop after going around once.

[Anonymous No.8044611]

>>8044593
That's... disappointing tbqh.

[Anonymous No.8044631]

>>8044592
who's going move the ball back to the original place?

[Anonymous No.8044634]

>>8044566
look & see

[Anonymous No.8044653]

Might be a dumb question, but:

Suppose you built a track for the magnets in a straight line, long enough to circle the earth. I know someone stated that traveling in a circle it would eventually stop, but considering how much speed and momentum the ball would gain wouldn't it just keep going? How could it stop?

[Anonymous No.8044655]

>>8044653
You don't seem to be getting the fundamental problem here. The contraption does not "reset" itself. The magnet configurations at the end are not the same that it started with.

[Anonymous No.8044662]

>>8044570
Magnets attract things because you dig magnets out of the earth. Because the earth contains GRAVITY, the magnet still has some gravity inside it and so attracts metal things because they want to return to the earth. This is why its called 'earthing' in electronics

[Anonymous No.8044667]

>>8044653
The momentum isn't infinite. Eventually it would stop due to friction.

Someone correct me if I'm wrong, but I think the faster an object is moving, the less velocity it will gain by receiving kinetic energy, since kinetic energy is proportional to velocity squared. So, it might not be going as fast as you think.

[Anonymous No.8044668]

>>8044566
>How is this not perpetual motion?
The same way as rolling a ball down a hill isn't perpetual motion. A system with a large amount of potential energy has been converted into a system with less, and that energy has been used to fling something away at speed.

[Anonymous No.8044678]

>>8044566
It takes energy to set that shit up. 1st of all the initial setup, of taping all the magnets to the ruler, but more importantly, placing the balls in that configuration takes energy.

In other, there is potential energy in that setup of balls and magnets, which is translated into kinetic energy when it's fired.

[Anonymous No.8044684]

>>8044655
congrats, at least one anon got it
while the rest is reciting prayers

[Anonymous No.8044714]

>>8044667
> I think the faster an object is moving, the less velocity it will gain by receiving kinetic energy
In absolute terms you're wrong.
But in relative terms it's right

[Anonymous No.8044718]

>>8044634
But can this be weaponized?

[Anonymous No.8044721]

>>8044718
More importantly, can it be Africanized?

[Anonymous No.8044725]

>>8044714
Because the object will gain mass until it has a huge mass, and hence huge momentum and kinetic energy, but the velocity will level off and barely increase.

[Anonymous No.8044728]

>>8044725
But that's when you start nearing light speed and is negligible at lower speeds.

[Anonymous No.8044752]

>>8044662
biutiful

[Anonymous No.8044756]

>>8044566
>>8044634
Not perpetual, even if it was in a circle you'd lose energy to friction and so on....
On the point of weapons, through purely this principal the size of the magnet required you may as well use gun powder.

[Anonymous No.8044833]

>>8044714
No, even in absolute terms. For example, if we have a 1kg object, it takes 150J of energy to accelerate it from 10m/s to 20m/s, but it takes 250J to accelerate it from 20m/s to 30m/s. This just comes from the expression for kinetic energy, 1/2*m*v^2.

If we assume that each magnet has about the same strength and each "link" in the chain is about the same distance, then the kinetic energy of the system is increasing by roughly the same amount each time. This means that each "link" of the chain gives the system less speed than the last, even though it is converting the same amount of potential energy to kinetic energy.

[Anonymous No.8044993]

>>8044575
>An object can move perpetually in a straight line.
That's not what people mean by perpetual motion, though. Otherwise a single particle moving through space would be perpetual motion. But of course linear velocity is relative, and that would mean perpetual motion depends on your frame of reference!

[Anonymous No.8045000]

At start, you got only one ball at magnet


At end you got two balls at magnet, which means you have twice as much stuff in ground state

[Anonymous No.8045013]

Now what, homos?

[Anonymous No.8045036]

>>8045013
congratulations, you just made this, but with much more friction and noise

[Anonymous No.8045055]

>>8044566
Because the ending configuration has lower potential energy that the start, with each second ball closer to a magnet instead of in the middle.

[Anonymous No.8045063]

>>8044662
hahah this has to be the best explanation i've seen. thanks anon i'll be using this from now on whenever someone asks me how magnets work

[Anonymous No.8045073]

>>8044718
Use one magnet and put a string on the first ball so you can reset it, and you'd have a magnetic BB gun. Or with a better resetting mechanism you could have multiple magnets (perhaps a rail that you'd lower onto the main rail and pull back as in this pic).

[Anonymous No.8045078]

>>8045073
Oops, drew the balls in the wrong position.

[Anonymous No.8045092]

>>8045073
>>8045078
Although it would be a little better if the resetting mechanism only separated one ball from a magnet at a time instead of all at once, which is going to require a lot more force.

[Anonymous No.8045098]

>>8045063
http://fakescience.org/how-do-magnets-work/