You need the know the
following before finding the gravitational force:
Acceleration due to
gravity at the North Pole of Neptune is 10.7 m/s^2
Neptune has mass of
10^(26) kg; and
Radius 25000 km
Rotates a time of about
16 hr.
So the gravitational force is computed by F = mg = 5.8 kg x
10.7N/kg ≈ 62 N
