
Mercury, the smallest of the eight recognised planets, has a diameter of and a mean density of . A man has a weight of 900 N on the Earth's surface. What would his weight be on the surface of Mercury?

Important Questions on Gravitational Fields

Ganymede is the largest of Jupiter's moons, with a mass of . It orbits Jupiter with an orbital radius of and it rotates on its own axis with a period of days. It has been suggested that to monitor an unmanned landing craft on the surface of Ganymede a geostationary satellite should be placed in orbit around Ganymede. Calculate the orbital radius of the proposed geostationary satellite.

Ganymede is the largest of Jupiter's moons, with a mass of . It orbits Jupiter with an orbital radius of and it rotates on its own axis with a period of days. It has been suggested that to monitor an unmanned landing craft on the surface of Ganymede a geostationary satellite should be placed in orbit around Ganymede.
(b). Suggest a difficulty that might be encountered in achieving a geostationary orbit for this moon.

The Earth orbits the Sun with a period of year at an orbital radius of Calculate:
(a). The orbital speed of the Earth

The Earth orbits the Sun with a period of year at an orbital radius of Calculate the centripetal acceleration of the Earth.

The Earth orbits the Sun with a period of year at an orbital radius of Calculate the Sun's gravitational field strength at the Earth

The planet Mars has a mass ofand a diameter of . Calculate the acceleration due to gravity at the planet's surface.

The planet Mars has a mass ofand a diameter of . Calculate the gravitational potential at the surface of the planet.
