If the planet mars is about 56 million kilometers from earth how long would it take for a radio wave sent from a space satellite circiling mars to reach earth
190 seconds.
The time the radio wave will take to reach Earth is the distance it needs to go divided by the speed of light which is 299792.458 km/s.
56000000 km / 299792.458 km/s = 186.7958933 s
Rounding to 2 significant figures gives 190 seconds.
