Chapter 2, Problem 129E

In 1999, scientists discovered a new class of black hole with masses 100 to 10,000 times the mass of our sun but occupying less space than our moon. Suppose that one of these black holes has a mass of $1\times {10}^3$

suns and a radius equal to one-half the radius of our moon. What is its density in grams per cubic centimeter? The mass of the sun is $2\cdot 0\times {10}^{30}$

kg, and the radius of the moon is $2\cdot 16\times {10}^3$

mi. (Volume of a sphere $=\frac{4}{3}{\text{πr}}^3$.)