Assuming that a neutron star is as dense as an atomic nucleus,estimate the mass of a neutron star having a diameter of 10 km.

Question

Quizplus · Accepted Answer

The radius of a neutron star is 10 km/2=5 km. 
Assuming the neutron star has the density of an atomic nucleus, its density would be approximately 2.3 x 10^17 kg/m^3. 
Using the formula for the volume of a sphere, V=(4/3)πr^3, we get V=(4/3)π(5,000 m)^3=523,599,000,000 m^3.
Multiplying the volume by the density gives us the mass: 
Mass = 523,599,000,000 m^3 x 2.3 x 10^17 kg/m^3
Mass = 1.20393 x 10^29 kg, which is approximately equal to 1.5 x 10^30 kg in scientific notation. Therefore, the best choice is A.

Assuming That a Neutron Star Is as Dense as an Atomic