(a) How far from the center of the earth is the center of gravity of the earth-moon system? (Note: the radius of the earth is 6400km)
(b) Where is the point in the earth-moon system where the force of gravity due to these bodies on a test mass will be 0?
(c) What is the magnitude of the force of gravity on the moon due to (i) the earth and (ii) the sun?
(d) When the moon is between the earth and the sun (i. e. new moon), what is the magnitude and direction of the acceleration of the moon? What is the magnitude and direction of the acceleration of the moon when the earth is between the moon and the sun (i. e. full moon)?