Part A The earth is negatively charged, while the ionosphere--the highest layer of the earth's atmosphere starting at about 100 km--is positively charged. We can think of the earth and the ionosphere as the electrodes of a large capacitor. Rocket experiments find that the potential difference between the earth and the ionosphere is typically 450 kV. The average surface charge density of the earth is measured to be -1.0 nC/m. What is the total charge of the earth? The earth's radius is 6.37 106 m. Express your answer with the appropriate units. a xa X.10n Q = Value Units Submit Previous Answers Request Answer Incorrect; Try Again; 3 attempts remaining Part B What is the capacitance of the earth+ionosphere system? Express your answer with the appropriate units. C = Value Submit Request Answer ? Units ?