Q:   The radius of the Sun is <B>R = 6.96 x 10<sup>8</sup> m</b>, and the
             mass of the Sun is <b>M = 1.99 x 10<sup>30</sup> kg</b>.

       Based on the figure above, a typical neutron star of mass 1.5 solar
             masses has a radius of 12 km.   Using these values, compute
             the density of a neutron star.

                               1.5  *   1.99 x 10^(30) kg
                density  =  ----------------------------------
                                (4/3) * pi * (12,000 m)^3



                         =  4.12 x 10^(17)  kg / m^3


  Q:   One teaspoon contains a volume of 5 x 10^(-6) cubic meters.
             One elephant has a mass of 5,000 kg.  How many elephants
             must be squished into one teaspoon to match the density of
             a neutron star?


                mass in spoon  =  4.12 x 10^(17) kg/m^3 * 5 x 10^(-6) m^3

                               =  2.06 x 10^(12) kg


                                  2.06 x 10^(12) kg
                # elephants    =  -------------------  =  4 x 10^(8) 
                                     5000 kg/elephant