Cueball moon (a featureless globe with no atmosphere, but the same mass and radius as our moon) has a mass of 7.4 X 10^(22) kg and a radius of 1.7 X 10^(6) m.
The appropriate tangential speed (in km/s) for a 10,000-kg spacecraft to achieve a circular orbit just above the surface is .

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up