7. An Earth-observing satellite can see only a portion of the Earth's surface. The satellite has horizon sensors that can direct the angle 6 shown in the accompanying gure. Let r be the radius of the Earth (assumed spherical) and h the distance of the satellite from the Earth's surface. V Satellite Earth a. Show that h = r(csc 6 1). b. Using r = 6378 km, nd the average rate of change of the distance from the satellite to the surface of the Earth, when 6 changes from 7r/ 4 to 7r/ 3. What are the units? 0. At what rate is the distance h changing when 6 = 72/ 6