Certain neutron stars (extremely dense stars) are believed to be rotating at about 1 rev/s. If such a star has a radius of 15 km, what must be its minimum mass so that material on its surface remains in place during the rapid rotation

1.9981 * 10^24 Kg

Explanation:

Given that

R = 15 * 10^3

ω = 1 rev/s = 2π rad/s

From;

g =GM/R^2  - Rω^2

If g = 0

M = R ^3ω^2/G

M = (15 * 10^3)^3 * (2π)^2/6.67 * 10^-11

M = 1.9981 * 10^24 Kg

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