I've got a question I'm working on: A communications satellite is in an orbit that is 3.2 X 10^7 m directly above the equator. Consider the moment when the satellite is located midway between Quito, Equador, and Belem, Brazil; two cities almost on the equator that are separated by a distance of 3.7 X 10^6 m. Find the time it takes for a telephone call to go by the way of satellite between these cities. Ignore the curvature of the earth. -- eek! I'm not sure where to start! Is this related to the speed of light in any way? thanks for the help!