Electrical fields vs. Gravitational fields?

Question

What are the differences/similarities between the two?

Thanks

Answer 1

Coulomb's law and Newton's law seem similar enough. The strength of force varies as 1/r^2, but if you take a quick look at Gauss' theorem, you may conclude that happens because of a property of space (surfaces at a distance increase in r^2). They both depend on the product of characteristics of particles and a physical constant. In both you can define potential and potential energy in similar ways. But similarities end there. Charge can be positive or negative, while mass is always positive. Electrical currents generate magnetic fields, and changing magnetic fields generate currents. You have nothing like it in mass "currents".



Basically... HTH !!

Answer 2

The Gravitational/Electric Force on an object is just that, the force it experiences due to the presence of mass/charge. The field intensity is the force per unit mass/charge; the force an object experiences is proportional to the intensity. The Gravitational/Electric energy probably means the potential energy an object possesses due to the presence of the field. I disagree with the above in that the force on a charge due to an electric or magnetic field would usually be called the Lorentz force. Electric forces are caused by electric fields only.

Answer 3

Catch has most of it.



One other important difference is long distance effects. Gravity exerts its power over the entire length/width/whatever of the universe. EM forces are local. Not that they can't reach just as far as gravity, but charges are canceled out over any distance. In other words, the net charge on, say, the sun is zero. Or if it has any charge it is canceled by a charge in the solar wind around it.

Answer 4

similarity:

both obey inverse square law.



difference:

in gravitational field, only attractive force

in electric field, attractive and repuslive forces are possible depending on the charges involved