The acceleration g (in m/s²) produced by the gravitational force of Earth on a spacecraft is given by g = 3.99 ×1014 /r², where r is the distance from the center of Earth to the spacecraft. On log-log paper, graph g as a function of r from r = 6.37 × 10⁶ m (Earth’s surface) to r = 3.91 × 10⁸ m (the distance to the moon).