Why Over-Unity is Possible

[lancaIV]

http://translationportal.epo.org/emtp/translate/?ACTION=description-retrieval&COUNTRY=DE&ENGINE=google&FORMAT=docdb&KIND=A1&LOCALE=en_EP&NUMBER=19706659&OPS=ops.epo.org/3.2&SRCLANG=de&TRGLANG=en

  I = 13,8 mA und U = 3 V                                Zugkräfte= traction forces about f.e. 1.000 N
   
                                                                        Hubkraft =  lifting    force ?


For the above concept instead /or with battery  a thermocouple/thermopile arrangement to get the high magnetic field force :
http://translationportal.epo.org/emtp/translate/?ACTION=description-retrieval&COUNTRY=DE&ENGINE=google&FORMAT=docdb&KIND=A1&LOCALE=en_EP&NUMBER=102004020962&OPS=ops.epo.org/3.2&SRCLANG=de&TRGLANG=en

[bitbo]

I hope we can agree that kinetic energy of the sack at the ground will be smaller comparing to the normal fall  from the same height as magnet slows down the fall.

Yes, everyone here should agree !

[/size]Now, where is this energy difference lost?
Gravity performed work.
So did magnet preventing fall at the beginning.
So who paid for this "slowdown"? Marcel

You gained a "speedup" when attaching the bullets ti the magnet!
(the magnet "liftet" the bullets the last centimeter - your hand did not need to lift the bullets the last centimeter)


Just my 2 cents [/size]

[memoryman]

As i said, get your units straight.
"It is accelerating upwards at equal or greater speed than gravity is accelerating it downwards, as the brass weight demonstrated. What this means is that the relative motion of the magnet is equal to or greater than 9.18 Ms/s." you meant : 9.18 m/s^2.
The magnet is attracted to the plate by an force > than g; the plate exerts a downward force so that the magnet remains motionless. The magnet does not move wrt the plate.

[MT]

You gained a "speedup" when attaching the bullets ti the magnet!
(the magnet "liftet" the bullets the last centimeter - your hand did not need to lift the bullets the last centimeter)

Yes, just this is another typical physics answer. A magnetic object in a magnetic field is somehow "precharged" to energy needed to get it out of there. Similarly in gravitation field an object at height h is somehow "precharged" to potential energy equals mgh. Using those concepts energy is conserved, there is no gain, total sum is zero.
But still gravity or magnetism can and does perform work. Where it gets it energy from? I can lift bullets to the bucket at ceiling but i need calories for this work. Then last centimeter is lifted by magnet. Eventually bucket will detach and fall down by gravity doing work. Did gravity or magnet got weaker by working? apparently not. Did they got energy for foing this from the teoretical physical concepts so it all fits the conservation law? This is hard to believe.
So what is the source that provides for gravity force that can perform infinite amounts of work?

[pauldude000]

As i said, get your units straight.
"It is accelerating upwards at equal or greater speed than gravity is accelerating it downwards, as the brass weight demonstrated. What this means is that the relative motion of the magnet is equal to or greater than 9.18 Ms/s." you meant : 9.18 m/s^2.
The magnet is attracted to the plate by an force > than g; the plate exerts a downward force so that the magnet remains motionless. The magnet does not move wrt the plate.

Actually, where my error comes in is saying 9.18 instead of 9.81 (9.806 to be more correct) Meters per second, per second. (Often referred to as s^2). Your reference and quote of my words in response to your claim of my units being incorrect was specifically concerning using Joules for work. Since Joules are the standard measurement of work, you were wrong. I did make an error, but you didn't even catch it.


Now, you are basically using the classic teachers work explanation model of the hypothetical waiter's tray. Once lifted to a position it requires no work to keep it in that position. However, anyone but a high-school level physics grad knows that such an example carries a caveat, in that it is true only if no other force is acting upon the tray. In our case, and in a real world case even considering the waiter's tray, this force is gravity. That type of purely mechanistic scenario ONLY deals with inertia and only works if the waiter can remove his support from the tray and it remains motionless (say on some spaceship sufficiently far from a significant source of gravity) which demonstrates no work is necessary to maintain the position of said tray.


This type of 'work' is often referred to stupidly as 'negative work', in that it is a matter of philosophy that someone had to invent such a silly notion, all because of an inherently badly worded and misleading moronic base definition. However, there is logically only work.

By the way, who cares if the magnet moves in relation to the plate? A drunk driver is not moving relative to the car that he used to smash through a brick wall, but that proves exactly the same thing as your example -- nothing. The plate is not the issue. Gravity and the magnetic force acting upon the mass of the magnet are the issue. The only purpose for the plate  in the scenario is that it will give the magnetic field something to pull against. The scenario could be easily modified by stating that the field of the magnet is capable of lifting only the 5g mass of the magnet, and your notation becomes irrelevant anyway, since the weight of the magnet itself cancels out any supposed pressure applied by the plate.