Newton’s Universal Law of Gravitation (Problem 33)

Earth is not a perfect sphere. Its radius as well as the value of g vary with latitude. (a) Calculate Earth’s mass given the acceleration due to gravity at the North Pole is $9.807m{\text{/s}}^2$ and the radius of the Earth at the pole is 6356.8 km.(b) Compare this with the accepted value of $5.972\times {10}^{24}\text{kg}$. Select the answer to part (a).