Question

Within a neutron star, the material at the center has a density of 1.0 x 10 18 kg/m 3 . If a small

Answer 1

Density of the neutron star is given as

$\rho = 1 \time 10^{18} kg/m^3$

Radius of the star is also given as

$R = 1 \times 10^{-5} m$

now in order to find the mass of star we can assume that star is spherical in shape

so here we can use

$V = \frac{4}{3}\pi R^3$

$V = \frac{4}{3}\pi (1 \times 10^{-5})^3$

$V = 4.2 \times 10^{-15} m^3$

now mass of the star will be given as

$M = \rho V = 4.2 \times 10^{-15} \times 1 \times 10^{18}$

$M = 4.2 \times 10^3 kg$

so weight of the star on the earth will be

$W = Mg$

$W = 4.2 \times 10^3 \times 9.8$

$W = 4.1 \times 10^4 N$

so weight on the earth is given by above equation