Question

Tides can be either due to Moon Gravitation pull or due to inertia. I am not very clear about how Tides are caused due to Inertia of Earth?

Answer 1

Dear Student

The moon's gravitational pull on the earth is strong enough to tug the oceans into bulge. If no other forces were at play, shores would experience one high tide a day as the earth rotated on its axis and coasts ran into the oceans' bulge facing the moon.

Inertia, the tendency of a moving object to keep moving affects the earth's oceans too. As the moon circles the earth, the earth moves in a very slight circle too, and this movement is enough to cause a centrifugal force on the oceans.

This inertia, or centrifugal force, causes the oceans to bulge on the opposite side facing the moon. While the moon's gravitational pull is strong enough to attract oceans into a bulge on the side of the earth facing the moon, it is not strong enough to overcome the inertia on the opposite side of the earth. As a result, the world's oceans bulge twice once when they are on the side of Earth closest to the moon, and once when they are on the side farthest from the moon.