A uniform, spherical planet has a spherical space at its center.
The radius of the surface of the planet is Rp= 8.9E7 m (8.9 x 10^7 m).
The radius of the central hollow space is Rh = 6.2E5 m.
The total mass of the planet is M= 7.5E28 kg.
The distance from the center to three designated points are:
Point a is distance Ra= 9.2E8 m from center, outside of the planet.
Point b is distance Rb= 5.8E4 m from center, within the hollow center.
Point c is distance Rc= 7.1E6 m from center. between inner and outer surface.
SEE ATTACHMENT FOR A DIAGRAM
Find the gravitational field of the planet at each of the three points.
One important fact relative to gravity fields of masses, is:
(1) The gravity field, g, within a hollow shell of matter is zero. (At each interior point, the gravity field of any one element exactly cancels that of the element diametrically opposite).
(2) At points exterior to a hollow shell of matter, its gravity field, g, is the same as if the entire mass of the shell were a point mass at its center. (Note that a point on the surface is included by this rule.)
From Newton's gravitation law, the ...