(9 points) 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 0 shown in the accompanying figure. Let / be the radius of the Earth (assumed spherical) and h the distance of the satellite from the Earth's surface. Satellite h Earth a. Show that h = r(csc0 -1). b. Using r = 6378 km, find the average rate of change of the distance from the satellite to the surface of the Earth, when O changes from 7 /4 to 7 /3. What are the units? c. At what rate is the distance h changing when 0 = 7/6