Lowering weight with magnets

Smiles35 · 06-01-2015 01:43PM #1

Just watching Jay Leno's car videos on youtube and he was on about a new sports car and the use of carbon fibre to save on weight. Just got me thinking would you be able to lower the weight of a vehicle more if you had one frame inside or on top of another frame in the vehicle 'hovering' on magnets?

I've done a diagram in the interests of science.

Outkast_IRE · 06-01-2015 01:46PM

Won't the bottom magnet have a downward force acting on it from the magnetic field that's holding the the top magnet away from it

Smiles35 · 06-01-2015 01:58PM

Outkast_IRE wrote: »

Won't the bottom magnet have a downward force acting on it from the magnetic field that's holding the the top magnet away from it

But that's just the push of the magnet, it would'nt be the full weight of what's on top. Or would it?

citrus burst · 06-01-2015 03:55PM

It's a nice idea you've got going there but let me ask you a question or two. What do you think would happen to the magnets if we took away the top slab? If we put a scales that fit exactly in between the two slabs, what would it read? Then if we played around with the strength of the magnets how would the scales act?

Smiles35 · 06-01-2015 04:31PM

citrus burst wrote: »

It's a nice idea you've got going there but let me ask you a question or two. What do you think would happen to the magnets if we took away the top slab? If we put a scales that fit exactly in between the two slabs, what would it read? Then if we played around with the strength of the magnets how would the scales act?

I'd expect the original weight of the top one to show as less on the scales. I would'nt really expect the strenth of the magnets to have bearing. If the top one if hovering then surely gravity has been 'defeated' to a certain extent.

Edit: Should have put wheels on my car pic.

06-01-2015 04:44PM

What you're saying is essentially equivalent to this:

The "magnetic force" lifting the top object exerts an equal and opposite force on the lower object. The overall weight of the car would not change

locum-motion · 06-01-2015 04:47PM

Nice 'understanding' of the basics of science there!

For every action there's an equal and opposite reaction.
So if the weight of the 'supported by magnets' part is being held up by the force of the magnets, then an exactly equal force is pressing downwards.

Actually, your system includes unnecessary weight in the form if the magnets that are effectively doing nothing, so your attempt at reducing overall weight has increased it.

citrus burst · 06-01-2015 04:49PM

Noblong wrote: »

I'd expect the original weight of the top one to show as less on the scales. I would'nt really expect the strenth of the magnets to have bearing. If the top one if hovering then surely gravity has been 'defeated' to a certain extent.

Why would you think that the strength of the magnet has no effect? Why for example is the top slab at the distance is it from the bottom slab? I wouldn't say gravity is "defeated" as much as I'd say "balanced"

Have a think about my questions in this post and the previous and maybe look up Newton's laws.

Noblong wrote: »

Edit: Should have put wheels on my car pic.

Yes you should have

djpbarry · 12-01-2015 02:00PM

Noblong wrote: »

I would'nt really expect the strenth of the magnets to have bearing.

So why not reduce the strength of the magnets to zero and remove them?

Smiles35 · 13-01-2015 04:49PM

djpbarry wrote: »

So why not reduce the strength of the magnets to zero and remove them?

I suppose I was only realy thinking of the ones you get at home that require no current.

13-01-2015 04:52PM

Noblong wrote: »

I suppose I was only realy thinking of the ones you get at home that require no current.

Those magnets still have a "strength". What would happen if you used really weak magnets, that couldn't lift the top frame at all? What would happen if you used magnets that were just strong enough to lift the top frame by a millimetre? Do you think there would be any difference in the overall weight between those two scenarios?

Smiles35 · 13-01-2015 05:11PM

28064212 wrote: »

Those magnets still have a "strength". What would happen if you used really weak magnets, that couldn't lift the top frame at all? What would happen if you used magnets that were just strong enough to lift the top frame by a millimetre? Do you think there would be any difference in the overall weight between those two scenarios?

I was just wondering if the 'natural' north/south repeling, and therefore allready balanced and sized magnets would have an effect on overall weight.

I'm getting the impression that's a no.

The_Captain · 13-01-2015 05:25PM

There's no 'impression' it's a no. It's an absolute fundamental rule of physics that the weight wouldn't change

Smiles35 · 13-01-2015 05:33PM

The_Captain wrote: »

There's no 'impression' it's a no. It's an absolute fundamental rule of physics that the weight wouldn't change

Ok Captain.

Dtp1979 · 13-01-2015 05:36PM

Maybe you've just invented a new type of suspension for vehicles

ScumLord · 14-01-2015 12:41PM

Dtp1979 wrote: »

Maybe you've just invented a new type of suspension for vehicles

I was thinking the same.

I guess the problem would be the weight added to the car would make it a useless upgrade. You would need a beefy electrical system to power those magnets. A big problem would be stopping the top magnet just falling off or going out of position, they'd need to be linked at which point you might as well use standard suspension.

The top magnet is still transferring it's weight to the bottom magnet it's just doing it through the magnetic field rather than through direct contact. You can already see your exerting a force on the top magnet, that force goes both ways. If I push down on the top magnet that force get's transferred to the bottom magnet, there's no reason to think gravity couldn't do the same thing.

Akrasia · 19-01-2015 01:31PM

I think there are suspension systems that do use magnets. It's basically a hydraulic suspension system that has magnetic filings in the fluid. When the suspension needs to be stiffer, magnets are activated which draws the filings into a chamber in the shock absorber and stiffens up the ride

http://en.wikipedia.org/wiki/MagneRide

Maximus Alexander · 21-01-2015 09:13PM

Hold the a magnet in your left hand with the north pole facing right.

Hold another magnet in your right hand with the north pole facing left.

Move the one on the left towards the one on the right.

Can you feel your right hand being pushed? This is why it won't work.

Lowering weight with magnets

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