The electric field has been measured to be vertically upward everywhere on the surface of a box 20 cm long, 4 cm high, and 3 cm deep, shown in the figure. All over the bottom of the box E1 = 1600 V/m, all over the sides E2 = 950 V/m, and all over the top E3 = 400 V/m. What is the amount of charge enclosed by the box? Use the accurate value ?0 = 8.85 10-12 C2/N·m2. C