00:01
So in this problem, we're asked to look at this diagram that we're given, and we're asked why doesn't the electric field have any z component, right? we know that it has x and y, but no z, but we know that the magnetic field or the b field does.
00:18
So if we just consider one of the plates here, for a positive sheet, the field is pointing away from the plate, and for a negative chart, the field is going to be pointing toward it.
00:34
So let's say e1 is the electric field is a small section of the positive plate, right? at some random point let's i don't know call it p right this point p our electric field is going to be pointing away, right? and for our plate on top our negative charge plate, that's going to be pointing toward our plate at point p, right? and looking at the geometry that we have, i know that i've technically written this opposite in our drawing over here, but looking at this over here, notice that we would have our negative, our negative e field pointing this way.
01:43
And we would have our positive one pointing this way, right? and we know that usually our e fields always have ex, ey, and ez, right? but in this case, they don't, right? this is because our ex and our ex and our or z components rather, of our e1 and in this case for our negative plate, that would be e2, are pointing in the same exact direction.
02:19
And this is because of the geometry that we have set up, where our negative field is pointing directly toward our positive field, right? so what we're going to have happen is some of the forces in our z component, it's going to be e1 plus the negative of e2, right? we already discussed that e2 with negative...