A 3.5 kg mass weighs 28.7 N on the surface of
a planet similar to Earth. The radius of this
planet is roughly 5.6 × 106 m.
Calculate the mass of of this planet. The
value of the universal gravitational constant
is 6.67259 × 10-11 N · m2/kg2.
Answer in units of kg.

Calculate the average density of this planet.
Answer in units of kg/m3.