Question

A neutron star has a mass of 1.27 × 1030 kg (about the mass of our sun) and a radius of 6.47 × 103 m. Suppose an object falls from rest near the surface of such a star. How fast would it be moving after it had fallen a distance of 0.0086 m? (Assume that the gravitational force is constant over the distance of the fall, and that the star is not rotating.)

Answer 1

assume you mean Mstar = 1.27*10^30
and r = 6.47 * 10^3

(1/2) m v^2 = Fg * .0086

Fg = G Mstar * m / r^2

so
v^2 = (2 G Mstar/r^2).0086

Answer 2

A neutron star has a mass of 2.1 1030 kg (about the mass of our sun) and a radius of 6.2 103 m (about the height of a good-sized mountain). Suppose an object falls from rest near the surface of such a star. How fast would this object be moving after it had fallen a distance of 0.013 m? (Assume that the gravitational force is constant over the distance of the fall and that the star is not rotating.)

Answer 3

fvhngghgh die adn fial