Satellite TV is broadcast from satellites that orbit 37,000 km above the earth's surface. Their antennas broadcast a 15 kW microwave signal that covers most of North America, an area of about 2.5×10^7km².

a. What is the total power that strikes a 75-cm-diameter ground-based dish antenna?
b. The dish antenna focuses the incoming wave to a 1.0 cm² area.
c. What is the amplitude of the electric field at this focus?