Instead of windmills along the road how about putting a tunnel over the road, one for each direction. As the vehicles go thru the tunnel they create wind flowing thru the tunnel which decreases wind resistance for everyone. In effect, you would always have the wind at your back. I suppose some vehicles would be made to take advantage of that, like having a sail. Gas mileage goes up to 100mpg. If the tunnel wind gets too strong it could be tapped to run a generator. Brilliant idea or what?
As the rotor is attracted to the next magnet it's also still attracted by the last magnet canceling out the tractor beam. You need a switch to turn on and off the magnets. Like some kind of brush system.
Someone may (or may not) find it an interesting fact of electrodynamics that the magnetic field can do no work. A charged particle moving in a magnetic B-field experiences a sideways force that is proportional to the strength of the magnetic field, the component of the velocity that is perpendicular to the magnetic field and the charge of the particle. This force is known as the Lorentz force, and is given by F = q( v x B ) If an electric field E is also present, the force is given by F = q( E + v x B ) Since the Lorentz force is partially the result of the cross product of the charge's velocity and magnetic field vectors ( v x B ), the force must point in a perpendicular direction to both. That means that the calculation for work will involve the dot product of two perpendicular vectors (the Lorentz force vector F and an differential distance vector whose direction always points in the direction of the velocity vector v) which ALWAYS equals zero since these two are always perpendicular vectors (F dot ds). Hence, the magnetic field can do NO work. Ask any physics student. The electric field can and does do work on charges. However, owing to the inseparable relationship between the electric and magnetic fields, the magnetic field can only do work indirectly - that is by the electric field generated by a CHANGING magnetic field. And now to really add something strange to the mix, as Richard Feynman showed in Vol 2 of his three volume classic, Feynman Lectures in Physics, the magnetic field doesn't actually exist as an independent entity apart from moving charges and/or changing electric fields. Even the magnetic field produced by a seemingly stationary bar magnet involves the motion of charges (or their quantum spin) in the magnet's atoms. The magnetic field and electric field are different aspects of the same thing - changes in one produces changes in the other. In fact, the magnetic field can viewed as a relativistic component of the electric field. The magnetic field strength and direction are entirely dependent on the choice of reference frame for making the measurements. An electric force perceived by one observer may be perceived by another (in a different frame of reference) as a magnetic force, or a mixture of electric and magnetic forces. Feynman Lectures, Vol 2 - Section 13-6: The relativity of magnetic and electric fields Feynman Lectures, Vol 2 - Section 1-5 (para. 3,4): What are the fields?
How could that be when a magnet can move another object? Work is force * distance. When a magnet attracts an object isnt that by definition doing work?
Here is an attempt at an analogy to remedy my confusion. Would this be akin to saying the waves in the ocean dont do work but cause the water to do work?
would be better to build a turbine directly ON a car so you charge up simply from driving, then an electric motor that gets charged simply from driving.
a magnet cannot move another object. A third party must push that object with the magnet. Think of the magnetic field as an extension of its physical state. You wouldn't say a metal bar does work -yuri
Why do you make a distinction between a magnet and its magnetic field in this way? A magnet can do no work but a magnets everpresent magnetic field can. Thats like saying a lightbulb cant burn you, only the heat it produces can.
The light bulb has no heat without adding an energy source just as a magnetic field can't move an object without an added energy source. I could be wrong, can someone provide an example of a magnetic field moving an object by itself? The field can be considered an extension of the magnet. Before it can move an object, the object must be moved to within the magnetic field. Your finger can push an object but you must first push your finger.
Say you have a neodymium magnet on the floor with the poles parallel to the floor. Now roll a steel marble perpendicular to the poles. The marble should keep moving in the direction you push it unless acted on by an outside force. There is no doubt when the ball encounters the magnetic field it will accelerate perpendicular to the direction it was rolling. Here is a warning from a site that sells them " If carrying one into another room, carefully plan the route you will be taking. Sensitive instruments like CRT monitors will be affected in an entire room. Loose metallic objects and other magnets may become airborne and fly at great speed to attach themselves to these magnets. If you get caught in between the two Supermagnets you can be severely injured or killed. These magnets will crush bones in the blink of an eye. Two of these magnets close together can create an almost unbelievable magnetic field that can be incredibly dangerous. Two Supermagnets can very easily get out of control, crush fingers and instantly break ribs or even your arm if opposing poles fly at each other. A small child recently lost his hand when his father left two # 31 supermagnets unattended. The child picked one up and when he approached the other magnet on a nearby table, it became airborne and obliterated his small hand." Btw these are permanent magnets which require no energy input, they are constantly ready to injure you!