Question

A neutron star has a density of about 5.9 10 17 kg/m3. What would be the approximate mass of a 1-centimeter cube (a cube 1 cm on all sides)? 5.9 1014 kg (1300 trillion pounds) 5.9 108 kg (1.3 billion pounds) 5.9 1017 kg (1.3 quadrillion pounds) 5.9 1011 kg (1.3 trillion pounds)

Answer 1

Density is usually stated as gm/cc
1 kilogram = 1*10^3 grams
1 cubic meter = 1*10^6 cc

5.9 x 10^17 kg/m^3 = 5.9 x 10^20 g/m^3
5.9 x 10^20 g/m^3 = 5.9 x 10^14 g/cc

So, the mass is 5.9x10^14 grams which equals
5.9 x 10^11 kilograms (which is the last answer).