Certain neutron stars (extremely dense stars) are believed to be rotating at about 0.70 rev/s. If such a star has a radius of 19 km, what must be its minimum mass so that material on its surface remains in place during the rapid rotation

The minimum mass so that material on its surface remains in place during the rapid rotation is  .        

Explanation:

Given that,

Certain neutron stars are believed to be rotating at about 0.70 rev/s.

Radius of the star, r = 119 km

When the star rotates the gravitational force is balanced by the centripetal force as :

So, the minimum mass so that material on its surface remains in place during the rapid rotation is  .