Question

Give reasons for the following:

Each day a tide is delayed by 26 minutes.

Answer 1

1. Each day, the tide is delayed by 26 minutes because the moon also rotates on its axis (west to east) while revolving around the Earth.
2. Since the Earth rotates from west to east, the tide centre shifts westward. When the tide centre completes one round, the moon’s position is ahead of the tide centre by that time.
3. The moon also revolves around the Earth, with the result that the tide centre takes another 52 minutes to come under the moon.
4. Thus, a particular tide centre takes 24 hours 52 minutes to come under the moon, but by that time, there is another tide at the opposite side of the referred tide centre, and this happens after 12 hours 26 minutes.