(a) Assuming for simplicity that Earth is a sphere of constant density, compute the rate of change in rotational angular momentum of Earth due to the tidal influence of the Moon. Is the change positive or negative?
(b) Treating the Moon as a point mass, estimate the rate of change in orbital angular momentum of the Moon. Is this change positive or negative?
(c) Comparing your crude answers to parts (a) and (b), what can you say about the total angular momentum of the Earth--Moon system over time?