See attached file.
Part b. From the definition of gravity field of the earth at the spaceship's location as 'the force the earth exerts on the spaceship divided by the mass of the spaceship' find the earth's field at that location.
Part c. Find the distance from the center of the earth to a point in space where the earth's gravity field is 2.5 nt/kg.
Newton's gravitation law, (1) F = G M m / r^2 expresses the force F between two masses, M and m, with distance r between their centers of mass. The letter G is the 'universal gravitational constant', the same value when using (1) for any two objects in the universe. ...
The solution explains the problem and the calculations to arrive at the answers to the questions.