In December of 2011 they announced that a planet has been discovered in a habitable zone around a star! It has clouds! It has twice the radius of the earth, but with the same density as earth, about 5.515 × 10^3kg/m3
. Find the new acceleration of gravity on the surface of this planet.

Explanation:

The density of earth is given by

and in terms of this density, we can write the acceleration due to gravity on earth as

Similarly, the acceleration due to gravity on this new planet is given by

We know that this planet has the same density as earth and has a radius 2 times as large. We can then rewrite as

volume: 22

density: 7.04

(75°f − 32) × 5/9 = 23.889°c