measuring the earths mass through its gravity Calculate the force of the earths gravity on a  above the earths surface if its mass is  small spheres of diameter 100mm fall through 20 degree celsius water.
{"Image DocumentName": "Journey to the center of the earth", "Image ImageDescription": "Suppose we drill a hole through the earth (radius RE, mass mE) along a diameter and drop a mail pouch (mass m) down the hole. Derive an expression for the gravitational force on the pouch as a function of its distance r from the center. Assume that the density of the earth is uniform.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}