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Problem 3) Proton in a cube [40 points] A proton (charge +e=1.6x10 9 C) is located at the center of a cube of side length a. a) Find the total electric flux @ through the closed cube surface. Use E. = 8.85x10-12_ N . m Hint: The result is independent of the side length a of the cube. b) Find the electric flux @ through one face ( f ) of the cube. Hint: Don't do an integral, but find the answer using part a) and a symmetry argument