page67 Published January 10, 2015 at 1024 × 768 in 1/5/15 – 1/9/15 (Vectors and Projectile Motion) 6.2 (extra credit front page. Once you determine the g of the planet, you will have to use the modified Newton’s Universal Law of Gravitation. g = G M / d^2 and rho = Mass / vol and vol = 4/3πr^3