a) Calculate the gravitational force between Sun and Earth by using Newton's universal gravitation
b) Because of the size of Earth (REarth = 6,371 km), the distance of a person on Earth from the center of Sun at midnight can be longer by at most 2REarth, than that at noon. Considering this distance difference, estimate the maximum difference in the gravitational force by Sun between at midnight and noon for a 70-kg man discuss the direction of this force by Sun.
c) Does this mean that everything on Earth is heavier at night?