The escape velocity from the surface of Mars (mass = 6.42 × 1023 kg, radius = 3.39 × 106 m) is approximately:

On Earth, g ≈ 9.8 m/s2. If an object is moved to a location where g = 0, its mass:

The force with which the Earth attracts an object is called:

Two stars of masses m and 2m at a distance d rotate about their common centre of mass in free space. Their period of revolution is: