A hollow spherical planet is inhabited by people who live inside it, where the gravitational field is zero. When a very massive space ship lands on the planet's surface, inhabitants find that the
Gravitational field inside the planet is
A) non-zero, directed away from the spaceship.
B) non-zero, directed toward the spaceship.
C) still zero.

Question

Quizplus · Accepted Answer

The gravitational field inside a hollow sphere is zero due to the symmetry of the mass distribution. However, when a massive object like a spaceship lands on its surface, it breaks this symmetry. The gravitational field of the spaceship itself will penetrate the hollow sphere, creating a non-zero gravitational field inside, directed toward the spaceship.

A Hollow Spherical Planet Is Inhabited by People Who Live