A space probe on the surface of Mars sends a radio signal back to earth a distance of 8.66x0^7 km. Radio waves travel at the speed of light (3:00x10^8 m/s . How many seconds does it take the signal to reach earth
d = V*T = 8.66*10^7km = 8.66*10^10 m.
3*10^8 * T = 8.66*10^10.
posted by Henry