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Problem 23 .2, we have this given electric field, and we have a cube sitting here in space, touching the x -axis, and then scooted along from the origin to go between one meter and three meters in x, so the side length of the cube is two meters.
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And we want to know what the electric flux is through the top, bottom, left, back, and total.
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So the electric flux, of course, integral of e .da.
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So here, on the top, y is a constant 2 meters, and da is equal to just the magnitude of da j hat.
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And so because this is at a constant y, the electric field is constant, we can just take that normal area vector thing for the top here that has a value of 4 meters squared j -hat and just dot that with here.
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So our flux for this side is negative 72 -new meters squared for kulom.
01:57
Up for the bottom, y is a constant zero meters.
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So this will just be 4 -i -hat minus 6 j -hat, or no, plus 6 -j -hat...