Find the acceleration due to gravity on the surface of Neptune ,given that the mass of Neptune is 16.7 times that of the Earth and the radius of Neptune is 3.89times that of Earth (Re=6380km).

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

If element x has 99 protons how many electrons does it have

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.