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, as shown in Figure 22.102. All over the bottom of the box E1 =...

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, as shown in Figure 22.102. All over the bottom of the box E1 = 1500 volts/m, all over the sides E2 = 1000

volts/m, and all over the top E3 = 600 volts/m. What can you conclude about the contents of the box? Include a numerical