Earth-Ionosphere Capacitance, The earth can be considered as a single-conductor capacitor (see Problem 24.67). It can also be considered in combination with a charged layer of the atmosphere, the ionosphere, as a spherical capacitor with two plates, the surface of the earth being the negative plate. The ionosphere is at a level of about 70 km, and the potential difference between earth and ionosphere is about 350,000 V. Calculate:

(a) The capacitance of this system;

(b) The total charge on the capacitor;

(c) The energy stored in the system.