College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

Exercise 40

A spherical shell is formed by taking a solid sphere of radius 20.0 cm and hollowing out a spherical section from the shell's interior. Assume the hollow section and the sphere itself have the same center location (that is, they are concentric). (a) If the hollow section takes up 90.0 percent of the total volume, what is its radius (b) Win at is the ratio of tine outer area to the inner area of the shell