Planet P has the same average density as the Earth but a radius three times that of the Earth.
(a) Express the mass of Planet P in terms of the Earth’s mass ME.
(b) Using your result from part (a), obtain an expression for the acceleration due to gravity gP at the surface of Planet P in terms of the Earth’s acceleration due to gravity gE.
(c) Show that gP=3gE.
(d) A package has a mass of 5kg. Calculate its weight on Planet P.
(e) Comment briefly on how the change in both mass and radius together leads to the increase in surface gravity, even though the planet is much larger in size.