Question

5. We have drawn several analogies between gravitational and electric fields. An example is their shared 1/(distance)2 dependence on field strength for, respectively, point masses and charges. In Physics 160 you saw that the gravitational field strength is zero everywhere inside a spherical shell of matter. We have now learned that the electrical field strength is also zero inside an isolated charged spherical conductor. However, we have also leaned that the electrical field strength, again by Gauss's Law, is zero everywhere inside an isolated conductor of any shape. Is this the case for gravity? (a) For example, is the gravitational field strength inside a cubical shell of matter zero anywhere?, (b) everywhere? (c) If it is not zero everywhere, in what respect is the analogy between the gravitational and electrical fields not complete?

Answer 1