If the planet Mars is should 56 million kilometers from Earth, how long would it take for a radio wave sent from a space satellite circling Mars to reach Earth? Assume that radio waves (a form of...

If the planet Mars is should 56 million kilometers from Earth, how long would it take for a radio wave sent from a space satellite circling Mars to reach Earth? Assume that radio waves (a form of electromagnetic radiation) travel at the speed of light.