Gravitational force: If the mass of the earth and all objects on it were suddenly doubled, but the size remained the same, the acceleration due to gravity at the surface would become
A) 4 times what it now is.
B) 2 times what it now is.
C) the same as it now is.
D) 1/2 of what it now is.
E) 1/4 of what it now is.

Question

Quizplus · Accepted Answer

The acceleration due to gravity at the surface of the earth is directly proportional to the mass of the earth and inversely proportional to the square of the distance from the center of the earth. Doubling the mass of the earth would result in doubling the gravitational force acting on objects at the surface of the earth. However, since the size of the earth remains the same, the distance from the center of the earth will not change, and therefore the acceleration due to gravity at the surface will double. Thus, the answer is 2 times what it now is (choice B).

Gravitational Force: If the Mass of the Earth and All