The moons of Mars, Phobos (Fear) and Deimos (Terror), are very close to the planet compared to
Earth?s Moon. Their orbital radii are 9,378 km and 23,459 km respectively. What is the ratio of the
orbital speed, v, of Phobos to that of Deimos?
A) 1.582 B) 3.956 C) 0.3998 D) 0.2528 E) 2.858