Slader By measurement, the electric field in a certain region of the Earth’s atmosphere is found to be vertically downward. At a height of 300m above the surface the electric field is 60 N/C. At a height of 200m the electric field is 100N/C. (a) Using Gauss’s Law find the amount of electric charge contained in a cube with an edge size of 100m. (b) Calculate the area of the Earth at its surface, assuming it is a uniform sphere. (c) If the field is 300 N/C near the Earth’s surface, use Gauss’s Law to calculate the total electric charge on the Earth, assuming the electric field is radially downward and constant in magnitude over the whole surface of the Earth.