Question

Planet Z is 9000 km in diameter. The free-fall acceleration on Planet Z is 10.0 m/s^2.What is the mass of Planet Z?

Answer 1

part two

What is the free-fall acceleration 1.00×10^4 km above Planet Z's north pole?

Answer 2

The value of surface acceleration, gs, for Earth is 9.81 m/s^2. For planet Z, is is nearly the same, just 1.9% higher.

gs is proportional to M/R^2, where M is the planet's mass and R is its radius

[M/R^2]z = 1.019 [M/R^2]earth
Mz/Mearth = 1.019 [Rz/Rearth]^2

The radius of the Earth is 6371 km. This equaiton will let you solve for the mass of planet Z divided by that of the earth