Before revision: This is what allows us to use the Earth's radius for r. The value obtained agrees approximately with the measured value of g. The difference may be attributed to several factors, mentioned above under " Variations ": The Earth is not homogeneous The Earth is not a perfect sphere, and an average value must be used for its radius This calculated value of g only includes true gravity.
After revision: This is what allows us to use the Earth's radius for r. The value obtained agrees approximately with the measured value of g. The difference may be attributed to several factors, mentioned above under " Variation in magnitude ": The Earth is not homogeneous The Earth is not a perfect sphere, and an average value must be used for its radius This calculated value of g only includes true gravity.