QUESTION: two permanent magnets usually repel both forever often which have high push not hard making a permanently magnetically levitated platform In which really does the ability to execute work are from?
ANSWER:One of the truths of electromagnetism is that a magnetic field never does work, you never get work (create energy) directly from a magnetic field. The explanation is always that an induced electric field is what actually does the work. The case of permanent magnets is more complicated than most to try to explain explicitly, so I will give a similar example, taken from the classic text Introduction to Electrodynamics, David Griffiths, Prentice Hall Publishers. In the figure to the right there is a constant current in the loop as indicated and there is a magnetic field pointing into the page in the cross-hatched area. The upward force on the loop is just right so that the weight, mg, levitates. Of course, right now, no work is being done since the force is not moving the mass. But, suppose that the field is now increased so the upward force now exceeds mg. Now the mass starts rising. The magnetic force is doing the work, right? Wrong! Before you increased the field the direction of the electrons’ velocity was to the left (don’t forget the electrons go in the direction opposite the current). But, when the loop starts moving up, the electrons now also have a component of their velocity upward and that gives rise to a component of the force on the electrons which is to the right; but this would reduce the current which we have stipulated to be constant. So the battery in the circuit (which is not shown but has to be there if there is a steady current) has to supply more energy than before and that is where the work done on the rising coil comes from the battery. This is really just Faraday’s law, an induced back EMF in the loop arises because of the changing flux. I know this is not the exact question you asked, but, trust me, all “where does the energy come from when magnetic fields seem to carry out functions” questions boil down to similar explanationsan electric field you forgot to think about.
QUESTION: why does the new electric force changes with the magnetic force giving specific speed on the observer we.e. exactly how try these dos forces physique established?
‘s the newton’s 3rd rules of movement getting violated here
ANSWER:Indeed, electronic and magnetic areas commonly something different, he or she is signs of a single industry, the fresh new electromagnetic industry. After you changes from figure of mention of some other swinging physique, your alter the mix of this Spanking Sites free dating new electronic and you can magnetized parts of the individuals fields. Like, a time charges at rest provides a natural digital profession; but if you see it off a moving physical stature of site, it’s one another an electric and magnetic community. It is way too in it to exhibit the facts right here. How come we however explore electric and you will magnetic industries from inside the primary physics programs is the fact, typically, they got extended to find the connections. The new electromagnetic industry isn’t an effective vector career, it is a great tensor career, an area which includes more step three components.
The electrostatic pushes try reddish and are generally equal and opposite
QUESTION: a keen electron moving perpendicular in order to a magnetic field enjoy lorentz force , here discover action but where’s the fresh new “equal and you can opposite” impulse force .
ANSWER: Industry is developed by a recently available somewhere and also the “impulse push” would be on that cord. Although not, you to definitely force isn’t fundamentally equivalent and opposite to your push toward electron. Newton’s 3rd laws, while the instructed from inside the elementary physics, is not really certainly genuine and you will magnetized pushes, as they are acceleration depending, are the most useful example to display which. Brand new contour suggests two self-confident costs moving with velocities found because of the black vectors. Brand new magnetized force considered from the particle moving horizontally try no since the job around (as a result of the almost every other charges) are no. The field as a result of the fees moving horizonatlly points right up out of monitor, so that the magnetized force (blue) on the other fees is to the best. The web based force for each particle was shown into the environmentally friendly and they are none equal neither contrary. Newtonian auto mechanics plays the latest versions within the electromagnetism and you will everything however all hangs together, but you have to include the time and you can impetus densities from brand new fields. This is exactly ways beyond the range of website to handle.
