Suppose Earth collapsed down to one- tenth of its present radius, while retaining all of its present mass. Compared to your present weight, your weight would then be
A) increased by a factor of 100.
B) unchanged.
C) reduced by a factor of 10.
D) increased by a factor of 10.
E) reduced by a factor of 100.

Question

Quizplus · Accepted Answer

The gravitational force is inversely proportional to the square of the radius. If the radius is reduced to one-tenth, the gravitational force (and thus weight) increases by a factor of (1/0.1)^2 = 100.

Suppose Earth Collapsed Down to One- Tenth of Its Present