My textbook expects me to show the torque exerted on Earth by the Moon on the ocean, that is 'ahead' of the rotation of the earth due to friction between the Earth and its ocean. However, I wouldn't know how to show this properly. The best I've found so far are things like this:
But here they only include the side of the earth facing the Moon; how about the other side?
So I understand that without the friction of the tides, the Eart would have faces the Moon 'symmetrically', but because of friction, we get an asymmetrical situation. But how to conclude this line of reasoning?
Is it that the gravitational force by the Moon is much smaller on the side of the Earth that isn't facing the Moon, and therefore we only really need to consider the torque applied on the side facing the Moon?