Radio signals travel at a rate of 3 × 10^8meters per second. How many seconds will it take for a radio signal to travel from a satellite to the surface of the Earth if the satellite is orbiting at a height of 7.5 × 10^6 meters?
4.0 × 103 seconds
2.5 × 102 seconds
6 seconds
2.5 × 10–2 seconds