EXERCISE 21


(a) A proton takes up a volume roughly equal to a cube 10^(-15) m on a side,
and has a mass of 1.67 * 10^(-27) kg.
How does its density compare to that of a neutron star?

(b) What is the density of a black hole with mass equal to that of the Sun?
How does its density compare to that of a neutron star?
The Sun's mass is about 2 * 10^30 kg.

(c) What is the density of a black hole with mass 5 billion times that of the Sun?
This is about the mass of largest black holes astronomers have yet discovered.
How does its density compare to that of a neutron star?