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toesockshoe
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Today my prof said that for a point charge the force is proportional to 1/r^2. For a line charge it is proportional to 1/r. For a sheet charge it is a constant and for a volume it is proportional to r. He also did some derivations but I don't see how this can be.
For example for a sheet charge how can a test charge that is a million meters away experience the same force that an object one millimeter away experiences? Then doesn't that mean if I make a sheet charge of say 100C, then I should be able to provide a resulting force on an object that is across the country ... because a sheet charge produces a uniform electric field regardless of position right? Obviously this doesn't happen because if someone create a sheet charge in Africa...a metal object here certainly doesn't not feel it all the way here in America. Same thing with a volume charge... How can an object further away from the charge feel a stronger attraction than something closer to the charge?
For example for a sheet charge how can a test charge that is a million meters away experience the same force that an object one millimeter away experiences? Then doesn't that mean if I make a sheet charge of say 100C, then I should be able to provide a resulting force on an object that is across the country ... because a sheet charge produces a uniform electric field regardless of position right? Obviously this doesn't happen because if someone create a sheet charge in Africa...a metal object here certainly doesn't not feel it all the way here in America. Same thing with a volume charge... How can an object further away from the charge feel a stronger attraction than something closer to the charge?